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WORKS 



CAVENDISH SOCIETY. 



FOUNDED 1846. 



HAND-BOOK 






\ 



OF 



C H E M I S T R 




; 



BY 

LEOPOLD GMELIN, 



PROrSSSOR 0# CHS1II8TRY IN TVLK UICrVRRSITr OF BBIDELBXRO, 

A.»D HRVBER OV VARIOUS LRARNED SOCIRTIKa Uf BERLIN, BONN, CATANIA, DRESDEN, FREIBURG, 

FRANKFORT, GdTTINGEN, HALLS, HAMBURG, HANAU, HEIDELBERG, JA8ST, LONDON, 

MARBURG, MUNICH, PARIB, PETER8BUR6H, YIEHRA, AND THE WETTERAU. 



VOL. V. 



METAL S — fcontiniied.J 



TRANSLATED BT 



HENRY WATTS, B.A.. F.C.S. 

ASSISTANT IN THE BIRKBECK LABORATORY, UNIVERSITY COLLEGE, LONDON. 



LONDON: 
PRINTED FOR THE CAVENDISH SOCIETY. 



MDCCCLI. 



CONTENTS OP VOL. V. 



Metals (continued)* 



CHAPTEa XXVIII. ZINC. 



Page 



Memoirs, &c. relating to Zinc .... 
Histoiy. — Sources.^Preparatioa 
Purification 
Properties .... 

Cox?onKDs OF Zinc. 

Zinc and Oxygen. 

Suboxide of Zinc I .... 

Zinc-oxide. — ZnO. 

Hydrate of Zinc-oxide 
Zinc-salts. 

Peroxide of Zinc 

Zinc and Hydrogen. 

Hydride of Zinc. 
Zincnretted Hydrogen gas ! 

Zinc and Carbon. 

Carbide of Zinc ? 
Carbonate of Zinc-oxide 

a. Octobasic— 6. Quadrobasic. 

c. With 2 At. acid to 6 At base 

d, Bibasic— tf. Monobasic 

^ Mangamferous Zinc-spar .... 
^ Ferrtiffinous Zinc-spar; Kapniie 9 
/• Acid salt .... .... 

Zinc and Boron. 

Borate of Zinc-oxide 

Zinc and Phosphorus. 

Phosphide of Zinc 
Hypophosphite of Zinc-oxide 
Phosphite of Zinc-oxide 

TOL. y. 



*••• 



*•.. .••« 

••«• 



••** 



t..* 



«•». 



t«M 



• •M 



■••. 



1 

I 

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.••• ...a *0 



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a 



vi 



CONTEXTS. 



Page 

Ordinary Phosphate of Zinc-oxide* 

a. Triphosphate .... .... *... .... 17 

b. Diphosphate. — c. Acid Phosphate .... 18 

Pyrophosphate of Zinc-oxide .... .... .... 18 

Metaphosphate of Zinc-oxide .... .... 18 

Zinc and Sulphur. 

Sulphide of Zinc .... .... .... .... 19 

Hydrated Sulphide .... .... .... 20 

Oxysulphideof Zinc .... .... .... .... 20 

Hyposulphite of Zinc-oxide .... .... .... 21 

Tetrathionate of Zinc-oxide .... .... .... 21 

Trithionate of Zinc-oxide .... .... .... 21 

Sulphite of Zinc-oxide.... .... .... .... 21 

Hyposulphate of Zinc-oxide .... .... 22 

Sulphate of Zinc-oxide. 

a. Octobasic.—6. Sexbasic. — c. Quadrohasic .... 22 

d. Bibasic .... .... .... .... 23 

e. Monobasic .... .... .... .... 23 

a. Mono-bydrated .... .... .... 24 

p. Bi-hydratcd.— y. With 3J At. w»tcr.— ^» Pentft-hydnted 25 

f . Scx-hydratcd. — f. Hepta-Hydrated. ,.., 26 

/. Bisulphate .... .... .... .... 26 

Sulphocarbonate of Zinc .... .... ..., 26 

Sulphide of Phosphorus and Zinc .... .... 26 

Zinc and Selenium. 

Selenide of Zinc ...« .... .... 27 

Hydrated Selenide .... .... .... 27 

Selenite of Zinc-oxide. 

a. Monosclenite.— 6. Biselenite.— ^ o. Qnadroselenite 27 

Seleniate of Zinc-oxide .... .... .... 28 

Zinc and Iodine. 

Iodide of Zinc .... .... .... .... 28 

Hydriodate of Zinc-oxide .... .... .... 28 

Oxy-iodide of Zinc .... .... .... 28 

Hydriodite of Zinc-oxide .... .... .... 29 

Iodide of Zinc-oxide ? .... .... .... 29 

lodate of Zinc-oxide .... .... .... .... 29 

Zinc and Bromine. 

Bromide of Zinc .... .... .. . 29 

Hydrobromate of Zinc-oxide..,. .... .... 29 

Bromate of Zinc-oxide .... .... .... 30 

Zinc and Chlorine. 

Chloride of Zinc .... .... ..., .... 30 

Hydrochlorate of Zinc-oxide .... .... 3] 






CONTENTS. 

Oxyddoride of Zinc .... .... 

Hypochlorite of Zino-ozide.... .... . 

Chlorate of Zinc-oxide 

Ferchlorate of Zinc-oxide .... .... • 

Zinc and Fluorine. 

Fluoride of Zinc 

Hydrofloate of Zinc-oxide 
Fluoboride of Zino .... •... 

Zinc and Nitrogen. 

Nitride of Zino .... .m. 

Nitrate of 2iino-oxide. 

a, Octohasic.— 6. Quadrobafiic. — o. Monobasio 
Zinc-oxide with Ammonia {Zinoate qf Ammoma) . 
Carbonate of Zinc-oxide and Ammonia^ 
Boride of Nitrogen and Zinc f .^ 

Ordinary Phosphate of Zinc-oxide and Ammonia 
Pyrophosphate of Zinc-oxide and Ammonia 
Metaphosphate of Zinc-oxide and Ammonia .... 
Ammonio-hyposulphite of Zin€H)xide .... 
Ammonio-hyposnlphate of Zinc-oxide 
Quadrobasic Zinc-sulphate with Ammonia 
Monobasic Zinc-sulphate with Ammonia. 

a. 6NH« + 2(ZnO;50»).— 6. 2NH' + ZnO,SO» 

e. NH" + ZnO 80« 
Bnlphate of Zinc-oxide and Ammonia 
Ammonio-iodide of Zinc 
Iodide of Zinc and Ammonium .... 
Ammonio-iodate of Zinc-oxide 
Ammonio-bromide of Zinc 
Ammonio-bromate of Zinc-oxide 
Ammonio-chloride of Zinc. 

a. 2NH»^nCL-ft. NH»,ZnCL-«. NH",2Zaa 
Chloride of Zinc and Ammonium 

Zino and Potassium. 

Alloy of Zinc and Potassium 
Zinc-oxide with Potash {Zinoate ofPotaA) 
Carbonate of Zinc-oxide and Potash 
Sulphate of Zinc-oxide and Potash 
Iodide of Zinc and Potassium 
Chloride of Zinc and Potassium 
Fluoride of Zinc and Potassium .... 

Zinc and Sodium. 

Alloy of Zinc and Sodium .... 
Zinc-oxide with Soda (Ztnooilff i/AMfa) 
Carbonate of Zinc-oxide and Soda 
Zinc-oxide with Fluxes 
Sulphate of Zinc-oxide and Soda 



vu 



Page 
31 

82 

32 

33 



83 
83 
33 

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4» 
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a2 



vm 



CONTENTS. 



Iodide of Zinc and Sodium .... 
Chloride of Zinc and Sodium 

Zinc and Barium. 

Iodide of Zinc and Barium . . 

Zinc and Magnesium. 

Sulphate of Zinc-oxide and Magnesia 

Zinc and Aluminum. 

Aluminate of Zinc-oxide 

Sulphate of Alumina and Zino-oxide: Zinc^um 

Fluoride of Aluminum and Zinc 

Zinc and Silicium. 

Silicate of Zinc-oxide : Zine^lanee 
Hjdrofluate of Silica and Zinc-oxide .... 
Silicate of Zinc-oxide and Potash .... 

Zinc and Tungsten. 

Tungstate of Zino-oxide 
Sulphotungstateof Zinc: ZnS^WS* 

Zinc and Molybdenum. 

Molybdate of Zinc-oxide 
Sulphomolybdate of Zinc .... 
Persulphomolybdate of Zino 

Molybdate of Zinc-oxide and Anunonia, and Molybdate 
of Zinc-oxide and Potash 

Zinc and Vanadium. 

Yanadiate of Zinc-oxide. 

a. Monovanadiate. — i. Bivanadiate 

Zinc and Chromium. 

Chromate of Zino-oxide. 

a. Dichromate. — b, Monochromate 
Chromate of Zinc-oxide and Potash 

Zinc and Uranium. 
Uranate of Zino-oxide 

Zinc and Manganese. 

Permanganate of Zino-oxide 

Zinc and Arsenic. 

Arsenide of Zino 
Axseniate of Zinc-oxide. 

a, Tris-arseniate. — b. Acid salt 
Hyposulpharsenite of Zinc .... 
Sulpharsenito of Zinc... 
Sulpharseniate of Zinc 
Arseniate of Zinc-oxide with Ammonia 



Page 
45 
45 

45 
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46 

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.... 48 

49 

.... 4tf 

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.... 49 
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.... 49 

50 
.... 50 



CONTENTS. 



IX 



Page 



Zinc and Antimony. 

Antimonide of Zino 
Antimoniate of Zinc-oxido 


«••• 


— o~ 

. 50 
.... 50 


Sulphantiinoniate of Zinc— SZnS^bS' .... 
Zino and Tellurium. 


•••• 


50 


Tellnride of Zino 
Tellurite of Zino-ozide 
Sulphotelliirite of Zinc— SZnS^TeS' 


*••• 


•*•• 51 

51 

.... 51 


Zinc and Bismuth. 






Alloy of Zinc and Bismutb ! 
Other Compounds of Zinc 


••*• 


51 

..•• 51 



2^^ 



Chapter XXIX. CADMIUM. 

Memoirsy &c — History. — Sources. — Preparation 

A roperues •••• •••• •*.. .*•• 

CoMPOUXDs OF Cadmium. 

Cadmium and Oxygen. 

Suboxide of Cadmium ! 
Cadmic Oxide. — CdO 

Hydrate of Cadmic Oxide .... 

Cadmic Salts 

Cadmium and Carbon. 

Carbonate of Cadmic Oxide 

Cadmium and Boron. 
Borate of Cadmic Oxide 



.... 



Cadmium and Phosphorus. 
Phosphide of Cadmium 
Hypophosphite of Cadmic Oxide 
Pbospbite of Cadmic Oxide 
Ordinary Pliosphate of Cadmic Oxide 
^ Pyrophosphate of Cadmic Oxide 
Metaphoephate of Cadmic Oxide 

Cadmium and Sulphur. 

Sulphide of Cadmium (jGreenoekite) 
Sulphite of Cadmic Oxide .... 
Hyposulphate of Cadmic Oxide.... 
Sulphate of Cadmic Oxide. 

a. Disulphate. — h. Monosulphate 
Sttlphocarbonate of Cadmium 

Cadmium and Selenium. 
% Selenitc of Cadmic Oxide 



52 
53 



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55 

56 

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58 

59 



CONTENTS. 



Gadminm and Iodine. 



Fagc 



Iodide of Cadminm .... .... .... 69 

lodateofCadmic Oxide .... .... .... 69 

Cadmiom and Bromine. 

Bromide of Cadmium .... .... .... 59 

Hydrobromate of Cadmio Oxide .... .... 60 

Bromate of Cadmic Oxide .... .... .... 60 

Cadminm and Chlorine. 

Chloride of Cadmiimi. 

Hydrochlorate of Cadmic Oxide .... .... 00 

Ferchlorate of Cadmic Oxide .... .... 00 

Cadminm and Fluorine. 

Flaorideof Cadmiun.... .... .... .... 61 

Cadmium and Nitrogen. 

Nitride of Cadmium ! .... .... .... 61 

Nitrate of Cadmic Oxide .... .... .... 61 

Ammoniacal Oxide of Cadmium .... .... 61 

Ammonio-hyposulphate of Cadmic Oxide .... .... 61 

Ammonio-sulphate of Cadmic Oxide .... .... 62 

Ammonio-iodide of Cadmium .... .... .... 62 

Ammonio-bromide of Cadmium .... .... 62 

Ammonio-bromate of Cadmio Oxide .... .... 63 

Ammonio-cUoride of Cadmium .... .... 63 

Chloride of Cadmium and Ammonium , .... .... 63 

Cadminm and Potassinm. 

Sulphate of Cadmic Oxide and Potash .... .... 63 

Iodide of Cadmium and Potassium .... .... 64 

Bromide of Cadmium and Potassium .... .... 64 

Chloride of Cadmium and Potassium .... .... 64 

Cadminm and Sodinm. 

Cadmium with Fluxes .... .... (^ 

Chloride of Cadmium and Sodium .... .... 64 

Cadminm and Calcium. 

Hypophosphite of Cadmic Oxide and Lime f ^.. 64 

Cadminm and Silicium. 

Hydrated Silico-fluoride of Cadmium ^ .... .... 64 

Cadmium and Tungsten. 
Tungstate of Cadmic Oxide. 

a. Monotungstate. — b. Bitungstate .... 65 

Sulphostungstateof Cadmium.^Cd8,WS' .... .... 65 

Cadmium and Molybdenum. 

Molybdate of Cadmic Oxide * .... .... 65 



CONTENTS. XI 

Pa«© 

Sulphomolybdate of Cadmium .... •... 65 

Pergulphomolybdate of Cadmium .... .... .... 05 

Cadmium and Vanadium. 

Vanadiate of Cadmic OxidOi 

a, Monovanadiate. — 6. Bivanadiate .... 65 

Cadmium and Arsenic. 

Sulpharsenite of Cadmium .^ .... .... 65 

Snlpharseniate of Cadmium .... .... 66 

Cadmium and Antimony. 

Sulphantimoniate of Cadmium m*. .... .... 66 

Cadmium and Tellurium. 

Sulphotellurite of Cadmium .... .... 66 

Other Compounds of Cadmium .... .... .... 66 

Chapter XXX. TIN. 

MemoirSy &c., relating to Tin .... .... .... 66 

History •—'Sources .... .... •••• .... .... 66 

Preparation on the large scale. — ^Properties .... mm 67 

Compounds of Tin. 

Tin and Oxygen. 

Stannous Oxide — SnO ••• .... ..^ 68 

Hydrate of Stannous Oxide .... .... 69 

Salts of Stannous Oxide, or Stannous Salts .... 69 

Oxides of Tin intermediate between SnO and SnO'. 

a. Sesquioxide. — Sn'O' .... .... 70 

h. Anomalous Stannate of Stannic Oxide ..•• 71 

Stannio Oxide. — Stannic Acid. — SnO' .... .... 71 

Anomalous Hydrate of Stannic Acid .... .... 73 

Ordinary Hydrate of Stannic Acid .M. »• 74 
Salts of Stannic Oxide, or Stannic Salts. 

a. Anomalous Stannic Salts .... .... 74 

fi. Ordinary Stannic Salts .... .... 75 

Salts of Stannic Acid ; Stannates. 

a. Anomalous Stannatee .... .... 76 

/9. Ordinary Stannates., .... 76 

Tin and Boron. 

Borate of Stannous Oxide .... .••• «•• 77 

Tin and Phosphorus. 

Phosphide of Tin .... .... „,. .... 77 

Phosphate of Stannous Oxide .,«. mm 77 

Phosphite of Stannic Oxide .... .... .... 77 

Phosphate of Stannous Oxide .... .... 78 



XU CONTENTS. 

Page 
Tin aad Sulphur. 

Stannous Sulphide, or Snlphostannous Acid. — SnS ..« 78 

Ilydroeulpliate of Stannous Oxide .... .... 78 

Sesquisnlphide of Tin. — Sn*S* „„ .... .... 79 

Hydrated Sesquisulphide .,« .... 79 
Stannic Sulphide, or Sulphostannic Acid. — SnS*. 

Bi-hydro6ttlpkate of Stannous Oxide .... 80 

Tetrathionate of Stannous Oxide ..;. .... .... 81 

Hyposnlpfaite of Stannous Oxide .... .... 81 

Sulphite of Stannous Oxide .... .... .... 81 

f Hyposulphate of Stannous Oxide? .... .... 81 

Sulplmte of Stannous Oxide. 

a, Basic Sulphate. — 6. Monosulplutte .... .... 81 

Sulphate of Stannic Oxide. 

a. Ordinary. — 6. Anomalous .... .... 82 

Stannous and Stannic Sulphocarbonates .... .... 82 

Tin and Seleniam. 

Selenide of Tin .... .... .... .... 82 

Selenite of Stannic Oxide .... .... .... 82 

Tin and Iodine. 

Stannous Iodide, cr lodostannous Acid. — SnI .... 82 

% Stannic Iodide, cr lodostannic Acid. — SnI' .... 83 

Stannous and Stannic lodates .... .... ,... 83 

Tin and Bromine. 

Stannous Bromide, or Bromoetannous Acid. — SnBr.... 84 

Hydrobromate of Stannous Oxide .... .... 84 

Stannic Bromide, or Bromostanuic Acid.— SnBr' .... 84 

Bromate of Stannous Oxide .... .... .... 84 

Tin and Chlorine. 

Stannous Chlonde, or Chlorostannous Acid. — SnCl .... 84 

Mono-hydrochlorate of Stannous Oxide ; Tin-sali .... 85 

Hydrated Stannous Oxychloride. — SnCl,8nO + 3Aq. 87 

Hydrochlorate of Sesquioxide of Tin .... .... 87 

Stannic Chloride, or Chlorbstannic Acid. — SnCP. 

Crystallized Hydrochlorate of Stannic Oxide .... 88 

Aqueous Hydrochlorate of Stannic Oxide. 

a. Ordinary.-—^. Anomalous .... .... 89 

Stannic Chloride vfiih Sulphur and Phosphorus .... 89 

Chlorostannate of Phosphuretted Hydrogen .... .... 89 

'^ r ' Stannic Chloride with Terchloride of Phosphorus .... 90 

Chlorosulphide of Tin.— SnS*,2SnCl' .... .... 90 

Chloride of Sulphur and Tin .... .... 90 

Sulphate of Stannic Chloride .... .... .... 91 

f lodochloride of Tm.— SnCl,SnI .... .... 91 

Tin and Flnorine. 

Hydroflnate of Stannous Oxide .... .... 92 

Hydrofluate of Stannic Oxide .... .... .... 92 



.CONTENTS. xiii 

Page 
Tin and Nitrogen. 

Nitrateof Stannous Oxide .... .... .... 92 

Nitrate of Stannic Oxide .... .... .... 92 

Nitric Oxide with Stannic Chloride .... .... 93 

Stannate of Ammonia .... .... .... 93 

Sulphoetaimate of Ammoniom .... .... 93 

Ammonio-protiodide of Tin.— 2NH",8nI ..^ .„, 93 

lodostannite of Ammoninm. — ^NH^I,2SnI .... 93 

Ammonio-protocIUoride of Tin. — NH»,2SnCl .... „.. 93 

Ammonio-bichloride of Tin.— NH«, SnCl" .... 93 

Chlorostannite of Ammonium. — ^NHH^l, SnCl + Aq. ,.., 94 

Chlorostannate of Ammonium ; Pink-aalt. — NH*Cl,8nCP 94 

Ilydrochlorate and Stannite of Ammonia .... .... 95 

Nitrate of Stannic Oxide and Ammonia.... .... 95 

Tin and Potassium. 

Alloy of Tin and Potassium .... .... ..„ 95 

Stannite of Potash .... .... .... 95 

Stannate of Potash. 

a. Ordinary Stannate. 

a, Monostannate .... .... .... 95 

fr Acid Salt .... .... ..., 9^ 

' b, Anomalons Stannate ; Fremy*s Metastannate of 

I*otash .... .... .... 95 

Siilphostannate of Potassium. — KS,Sn,S* .... .... 9Q 

lodostannite of Potassium. — KI,2SnI J... .... fyj 

Chlorostannite of Potassium.— 2KCl,6nCl + 3 Aq. 

Clilorostannate of PotJBssiom. — KCl^SnCl* .... .... 97 

Hydrochlorate and Stannite of Potash .... .... 93 

Tin and Sodium. 

Alloy of Tin and Sodium .... .... ,.„ 93 

Stannite of Soda .... .... .... 93 

Stannate of Soda: a. Ordinary. — b. Anomalous .... 93 

Sulphostannate of Sodium .... .... .... 93 

lodostannite of Sodium .... .... .... 93 

Chlorostannate of Sodium .... .... .... 93 

Hydrochlorate and Stannite of Soda .... .... 99 

Tin and Barium. 

Stannate of Baryta .... .... .... 99 

Sulphostannate of Barium .... .... .... 99 

lodostannite of Barium .... .... .... 99 

If Chlorostannite of Barium.— BaCI, SnCl + 4Aq. .... 99 

^ Chlorostannate of Barium.- BaCl, SnCl* + 6Aq 99 

Hydrochlorate and Stannite of Baryta .... .... 99 

Tin and Strontium. 

Stannate of Strontia .... .... .... 99 

Sulphostannate of Strontium .... .... .... 99 

lodostannite of Strontium .... .... .... 99 



\ 



ZIV 



Page 



• •••• 



CONTENTS. 

% ChloroBtanniteofStrontiran.— SrCl^na+4Aq. 
f ChloroBtannate of Strontium.— SrCl,Sna'+ 6 Aq. 
Hydrochlorate and Stannite of Strontia.... 

Tin and Calcium. 

Stannate of Zinc .... •••• 

SulphoBtannate of CSakiuiu .... 

Tin and Magnesinm. 

Stannate of Magnesia.... ...• ••>• 

^ ChlorofltannateofMagnemum.— MgCl^nCl*+5Aq. 

Hydrochlorate and Stannite of Magnesia 

Tin and Silicium. 

Silicide of Tin .... 

Silicoflaoride of Tin .... .... •••• 

Tin and Tungsten. 

Tongstate of Stannous Oxide 

Stannous Sulphotnngstate. — SnSyWS^ .... 

Stannic Sulphotungstate.— SnS%WS^ .... 

Tin and Molybdenum. 

Molybdate of Stannic Oxide 
Stannous Salphomolybdate .... 
Stannic Sulphomolybdate 
Stannous Persulphomolybdate 
Stannic Fersulphomolybdate 

Tin and Chromium. 

Stannate of Chromic Oxide ? •..• 

Chromate of Stannous Oxide 
Chromate of Stannic Oxide 

Tin and Manganese. 

Stannate of Manganous Oxide .... .... .... 102 

Tin and Arsenic. 

Arsenide of Tin. 

Arsenite of Stannic Oxide^ or Arseniate of Stannous Oxide ! ] 02 

Stannous Sulpharsenite .... .... .... 102 

Stannic Sulpharsenite .... .... .... 102 

Stannous Sulpharseniate .... .... .... 103 

Stannic Sulpharseniate .... .... .... 103 

Bichloride of Tin with Terchloride of Arsenic .... 103 



• •a. 


99 




99 


.... 


100 




100 


.... 


100 




100 


MM 


lOO 




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.... 


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102 



Tin and Antimony. 

Antimonide of Tin 
Antimoniate of Stannic Oxide 
Stannous Sulphantimoniate.... 



103 
103 
104 



CONTENTS. 

Tin and Tellnrinm. 

Telloride of Tin 

Stannous Sulpothellurite ...• 

Stannic Sulphotellurite 

Tin and Bismnth. 

Alloys of Tin and Bismnth .... 
AUoj of Antunony, Bismnth and Tin 

Tin and Zinc. 

Alloys of Tin and Zinc 
Stannate of Zinc-ozide 

Othei Componnds of Tin .... 



XV 

Page 

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104 

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106 
.... 105 

106 



Chapteh XXXI. LEAD. 



27- 



Memoirs^ &c. — History. — Sonrces 

Preparation on the lai^^e scale.-' Purification. — Properties 

Compounds of Lead. 

Lead and Oxygen. 

Suboxide of Lead. — ^Pb'O I 

Lead-oxide. — ^PbO 

Hydrate of Lead-oxide 

Aqneons Solution of Lead-oxide .... 

J-^C84**' 9m t8 •••• •••< .... .... 

Red Oxide of Lead.— Pb'O* 
Sesqnioxide of Lead! — Pb*0^ 
Peroxide of Lead. — ^PbO' 

Lead and Carbon. 
Carbide of Lead t 

Carbonate of Lead-oxide. 

a. Bibasic Carbonate 

b, Sesquibasic Carbonate: White Lead 
0, Monobasic Carbonate : Lead-spar 

d. Five-fourths Carbonate .... 
e. Acid Carbonate 

Lead and Boron. 

Borate of Lead-oxide 

Lead and Phosphorus. 

Phosphide of Lead .... 

Hypophosphite of Lead-oxide «... 

Phosphite of Lead-oxide. 

«• Quadrobasic.— ^. Bibasic .... 



105 

106 



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108 

.... 113 
114 
116 

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120 

.... 120 



122 

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123 

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127 

.... 127 



128 



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128 

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Xvi CONTENTS. 

Page 
Phosphate of Lead-oxide. 

a. Terbasic. — b. Bibasic .... ... 130 

e, 3 At. Acid to 4 At. Basa— rf. With excess of Acid 131 

Pyrophospliate of Lead-oxide^ .... .... 131 

Metaphosphate of Lead-oxide . .. .... .... 131 

Lead and Salphnr. 

One-fonrUi Sulphide of Lead .... .... 132 

Disalphide of Lead .... .... .... •••• 132 

Protosnlphide of Lead : Galena .... .... 132 

Pentasulphide of Lead .... .-.. •••• 134 

Hyposulphite of Lead-oxide .... .... 135 

Tetrathionate of Lead-oxido .... .... -.. 135 

Trithionate of Lead-oxide .... .... ... 135 

Sulphite of Lead-oxide .... .-.• •— 135 

Hyposulphate of Lead-K>xide. 

a. Terbasic. — b. Bibasic f — c. Monobasic .... 135 
Sulphate of Lead-oxide. 

a. Basic. — ft. Monobasic : Lead-vUriol .... .... 136 

Sulphate and Carbonate of Lead-oxide : LeadhillUe..., 138 

Sulphocarbonate of Lead .... .... •••• 138 

Lead and Selenium. 

Selenide of Lead .... ••.• •••• •••• 139 

Selenite of Lead-oxide. 

a. Basic. — b. Monobasic .... .... 139 

Seleniate of Lead-oxide .... •— •— 1^9 

Lead and Iodine. 

Iodide of Lead.... .... •••. — • ^^® 

Oxy-iodide of Lead. 

a. PbI,PbO .... .■ •••• — 1^1 

b. PbI,2PbO ... . •. •• • 1^2 

Iodide of Lead and Hydrogen .... .... •.■• 1^2 

Basic Periodite of Lead-oxide ? 

a. Blue Salt.— 6. Violet Salt .... .... 143 

lodate of Lead-oxide .... •••• •••• *^^ 

Periodate of Lead-oxide .... .••. •••• ^** 

Lead and Bromine. 

Bromide of Lead .... .... •— •••• '^^ 

Oxybromide of Lead .... •••. *^* 

Bromate of Lead-oxide .... •••• — • ^^* 

Bromo-carbonate of Lead .... .... •••• i*** 

Lead and Chlorine. 

Chloride of Lead: Plumum comeum; Cotunniie .... 1*5 
Oxy chloride of Lead. 

a. 3PbCl, PbO— 6.Pba, PbO .- ^^^ 

c. PbCl, 2PbO : MendipUe •- •••• ^^^ 

d. Pba, 3PbO.— e. PbCl,6PbO.-/. Catfel-ffdhw 147 





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151 



CONTENTS. XVll 

Chlorite of Lead-oxide 
Chlorate of Lead-oxide 
Perchlorate of Lead-oxide 
ClilorocarboDate of Lead : Horn-lead 
Clilorophosphite of Lead 
Chlorophosphate of Lead : Ppromorphtte 
Chloroeulphide of Lead 
Chlorosulphate of Lead 
Chloriodide of Lead .... 

Lead and Fluorine. 
Flnoride of Lead 
Oxyfluoride of Lead .... 
Borofluoride of Lead.— FbF, BF 
Chlorofluoride of Lead.— PbCl, FbF .... .... 151 

Lead and Nitrogen. 

Nitrite of Lead-oxide, 

a. Qoadrobasic 
f b, Terbasic 1~^ e, Bibaaic— <d. Monobasic 
Hyponitrate of Lead-oxide. 

a. Qoadrobasic! 

5. Bibasic 
Nitrate of Lead-oxide 

a. Sexbasic. — b, Terbasic 

0. Bibasic. — d. Monobasic 
Boronitraie of Lead I 
Phosphonitrate of Lead-oxide 
if Azophosphate of Lead-oxide 

Nitrate of Lead-oxide with Fluoride of Lead 
Plumbite of Ammonia 
Hyposulphite of Lead-oxide and Ammonia 
Sulphate of Lead-oxide and Ammonia .... 
Ammonio-iodide of Lead 
Iodide of Lead and Ammoninm 
Ammonio-chloride of Lead 
Chloride of Lead and Ammonium 

Lead and Potassium. 

Alloy of Lead and Potassium 
Plnmbite of Potash 
Plumbate of Potash .... 
Hyposulphite of Lead-oxide and Potash 
Sulphate of Lead- oxide and Potash 
Iodide of Lead and Ammonium. 
a, 2KI, Pbl*.— 6. 2KMPbI 
Bromide of Lead and Potassium .... 

Lead and Sodium. 

Alloy of Lead and Sodium' .... ... .... 182 





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152 


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xviii CONTENTS. 

Page 

plmnbite of Soda .... «... •••« ^^ 

Plumbate of Soda .... .... ...• ..«• 162 

Carbonate of Lead-oxide and Soda .... .... 162 

Sulphide of Lead and Sodium .... .... .... 162 

Hyposulphite of Lead-oxide and Soda .... .... 162 

Sulphate of Lead-oxide and Soda.... .... .... 163 

Iodide of Lead and Sodium .... ••.. ..^ 163 

Bromide of Lead and Sodium .... .... .... 163 

Chloride of Lead and Sodium .... .... 163 

Lead and Barium. 

Plumbite of Baryta .... .... ..., .... 163 

^^ Sulphide of Lead and Barium .... .... 163 

Hyposulphite of Lead-oxide and Baryta .... .... 163 

Chloride of Lead and Barium .... .... 163 

• 

Lead and Strontium. 

Hyposulphite of Lead-oxide and Strontia .... .... 164 

Lead and Calcium. 

Plumbite of Lima .... .... .... 164 

Carbonate of Lead-oxide and Lime : Phmba-eateUe .... 164 

Hyposulphite of Lead-oxide and Lime.... .... 164 

. Phosphate of Lead-oxide and Lime with Chloride of Lead 164 

Sulphate of Lead-oxide with Fluorspar .... .... 164 

Lead and Aluminum. 

Phosphate of Lead-oxide with Hydrate of Alnmir^ft : 

Plombffommt ,.,. .... .... l$5 

Lead and Silicium. 

Silicide of Lead ... .... .... .... iq$ 

Silicate of Lead-oxide .... .... .... 1(J5 

Borosilicate of Lead-oxide .... .... .... igs 

Silicofluoride of Lead .... .... .„. iqq 

Silicate of Lead-oxide and an Alkali. 

a. Lead-glass. — h. Containing a large proportion of 

alkali .... .... .... ,.., igg 

Silicate of Zirconia and Lead-oxide. 

a. 2PbO,2ZrO,SiO^— 6. PbO,2ZrO,8iO« .... 166 

Lead and Titanium. 

Fluoride of Titanium and Lead .... .... ,.,. iqq 

Lead and Tantalum. 

Fluoride of Tantalum and Lead .... .... i^ 

Lead and Tungsten. 

Tungstide of Lead .... .... .... .... 166 

Tungstate of Lead-oxide.— a. Monotnngstate : ScheeRtme 166 

b. Bitungstate .... .... ^.. .... 167 

Sulphotungstate of Lead : PbS.WS' .... ..„ )67 



CONTENTS. XIX 

Page 
Lead and Molybdenum. 

Molybdide of Lead .... .... .... .... 167 

Molybdate of Lead-oxide : VeUcw Isad-WB .... 167 

Sulphomolybdate of Lead .... .... 168 

Persnlphomolybdate of Lead .... .... 168 

Lead and Vanadiam. 

Vaoadiate of Lead-oxide. 

a, Monovanadiate. — 6. Biyanadiate .... .... 168 

Vanadiie .... .... .... •..* 169 

Lead and Chromlam. 

Chromate of Lead-oxide. 

a, Dichromate : Chrome-red .... .... .... 169 

b, Sesquibasic Chromate : Melanochroiie .... 170 

c, Monochromate: Hed Lead-spar; Chrome-yelkw .... 170 

Lead and Uraniam. 

Uianate of Lead-oxide.^PbO,2U'0' .... .... 173 

Lead and Manganese .... .... .... .... 172 

Lead and Arsenic. 

Arsenide of Lead .... .... ««• 172 

Arsenite of Lead-oxide. 

a. Bibasic.— 5. Monobasic .... .... .... 173 

Arseniaie of Lead-oxide. 

a. Terbasic. — 6. Bibasio .... .... 173 

Solpbarsemte of Lead.— 2PbS^ AfiS^ .... .... 174 

Sulpbarseniate of Lead .... .... .... 174 

Arseniate of Lead-oxide with Chloride of Lead .... 174 

Arsenide of Lead and Potassium .... .... 174 

Lead and Antimony. 

AntimonideofLead.— tf. Pb'*^' .... .... 174 

b, Vh*^h.— Type-metal .... .... 176 

Antimoniate of Lead-oxide : iVap/!?« F9iZ0Co .... .... 175 

Sulphantimonite of Lead. 

a. Sexbasic: Kilkbrickenite .... .... 175 

b. Qointobasic : Geocronite»^-c, Terbasic : Boulangeriie 176 

d, Bibasic : Feather-ore, — e. Sesquibasic : Jameeonite 176 
/. Four- thirds-basic : PlaffUmite .... .... 176 

ff. Monobasic: Zinkenite .... .... 177 

Bulphantimoniate of Lead .... .... „.. 177 

Lead and Tellurium. 

Telluride of Lead .... .... .... 177 

Tellurite of Lead-oxide .... .... .... 178 

Tellurate of Dead-oxide .... .... .... 178 

SulphoteUurite of Lead .... .... .. . 178 



XX CONTENTS. 

Lead and Bismnth. 

Alloy of Lead and Bismnth .... .... .... 178 

Solpkobismutbate of Lead.— 3PbS,Bi8' : KobeiiUe •.- 179 

Lead and Zinc. 

Alloy of Lead and Zinc .... .... •.•• 179 

Lead and Tin. 

Alloys of Lead and Tin .... .... .... 179 

Stannate of Lead-oxide .... .... .... 180 

Antimonide of Lead and Tin .... .... .... 180 

Alloys of Bismuth, Lead and Tin .... .... 189 

Alloys of Lead^ Tin and Zinc .... .... .... 181 

Other Gomponnds of Lead .... .... .... 181 

CHATTfift XXXn. IRON. 

Memoirs, &c. — ^History.-— Sources.— Preparation on the lai^ scale 182 

Purification.-— Properties .... .... .... 183 

Compounds of Irox. 

Iron and Oxygen. 

Oxidation of Iron ..m .... .... .... 184 

Suboxide of Iron. — FeH)1 .... .... .... 187 

Ferrous Oxide FeO .... .... ..^ 187 

Hydrate of Ferrous Oxide .... .... 187 

Ferrous Salts :— Pfo/o-Mii^« o/Zftm .... «... 188 

Ferroso-ferric Oxide. 

a. Scsle-oxide: 6FeO, Fe'O*.— (. Magnetic Oxide: 

FeW or PeO,FeK>« .... .... 190 

Hydrate of Ferroso-ferric Oxide. 

a. D|]iS7 green Hydnte.»/3. Blick Hydnte .... .... 192 

Ferroso-ferric Salts .... .... .... 194 

Ferric-oxide.— Fe*0» .... .... .... 194 

Hydi-ate of Ferric-oxide : Brown Iron-ore .... 196 

a. Fe<OS,nO: JfetdU Iron-ore: Gdthite; LepidokrokiU i 

Pteudomorphotu Brown Iron-ore .... .... 197 

fi.9TB*0^,SB0'. Brown H€enuUiU ,.., .... 197 

y. Fe>OS^HO .... .... .... 198 

Ferric Salts : Per'saUt oflnm .... .... 198 

Ferric Acid. — ^FeO'? .... .... .... 201 

Iron and Hydrogen. 

Fermretted Hydrogen gas ? .... .... 201 

Iron and Carbon. 

Carbide of Ii-on .... .... .... .... 202 

a. Bar or Wrought Iron .... .... .... 205 



CONTENTS. 



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210 
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223 

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223 



i. Steel .... 

e. Cast-iron or Pig-iron 

A. White Pig-iron 

B. Grey Pig-iron 
d, Piire or Saturated Cast-iron : Fe^C 

Carbonate of Ferrous Oxide. 

a. Monobasic : Irtm^ipar or Spathic Iron-ore; Spharo^ 

wUrite; Junkerite.,,, .... .... 219 

5. Acid Carbonate .... .... .... 221 

Carbonate of Ferric Oxide ! .... .... 222 

Iron and Boron. 

Borate of Ferrous Oxide .... .... .... 222 

Borate of Feiric Oxide .... .... .... 222 

Iron and Phosphoras. 

Phosphide of Iron.— a. FeT 

b. Fe'P" .... 
Hypophosphite of Ferric Oxide 
Hypophosphate of , Ferric Oxide 
Phosphite of Ferrous Oxide 
Phosphite of Ferric Oxide .... 
Phosphate of Ferrous Oxide. 

a. Terbasic : Blue Iron-ore or Vivianite .... 

b, Bibadc.— iT. Acid Phosphate 
5r Pyrophosphate of Ferrous Oxide .... 

Phosphate of Ferric Oxide. 

a. Polybasic: Limonite 

b, Bibasic .... 

c. Sesquiphosphate 

d, Biphosphate ! 
^ Pyrophosphate of Ferric Oxide .... .... 

^ Metaphosphate of Ferric Oxide 

Iron and Sulphur. 

One-eighth Sulphide of Iron 

Disulphide of Iron 

Protosulphide of Iron, or Ferrous Sulphide .... 

Hydrosulphate of Ferrous Oxide .... 
Eight-seyenths Sulphide of Iron : Magnetio Pyritee 
Sesquisulphide of Iron, or Ferric Sulphide 

Hydrosulphate of Ferric Oxide 
Bisulphide of Iron : Iron Pyritea .... . 

Sulphide of Ferrous Oxide t 
Hyposulphite of Ferrous Oxide 
Sulphite of Ferrous Oxide 
Sulphite of Ferric Oxide 
Hyposulpliate of Ferrous Oxide .... 

Hyposulphate of Ferric Oxide 

Sulphate of Ferrous Oxide : Protosulphate of Irony Green 

Vitriol, Copperae .... .... „., ..„ 287 

VOL. V. h 



223 

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225 

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...a iCSv 

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232 
.... 835 

235 
.... 236 

236 

.... 2S*SO 

237 



xxii CONTENTS, 

Page 
cbMono-bydratod. — ^^.Bi-hydrated. — y.Ter-hydraied.. .. 239 

d. Tetra-hydrated. — t, Hepta-hydrated .... 239 

Sesquisulphate of Ferrous Oxide f .... .... 241 

Sulphate of Ferric Oxide. 

a. Sex-basic .... .... .... 241 

b. Quadrobasic — c. Terbasic .... .... ..^ 242 

d, Bibasic : VUriol'Ochre .... .... 242 

e. Monobasic .... .... .... '.... 243 

/. Sesquisulphate]: Fibrcferrite .... .... 243 

g, Bisulphate .... .,.. .... .... 243 

h. Tersulphate ; Normal Ferric Sulphate .... 244 

CoquimbUe .... ... .... .... 246 

Ferrous Sulphocarbonaie .... .... .... 245 

Ferric Sulphocarbonate .... .... .... 246 

Ferrous Hyposulphophosphite. — FeS,FS .... 246 

Ferrous Sulphophosphite.— 2FeS,PS'. 
Fhosphosulphate of Ferric Oxide: Diadoehiig 

(Fe*0%2PO* + 8Aq.)+4(Fe«0';SO» + aAq.) .... 246 

Iron and Seleniam. 

Selenide of Iron .... .... .... 246 

Selenite of Ferrous Oxide. 

a, Monoselenite. — b, Biselenite .... .... 247 

Selenite of Ferric Oxide. 

a, Sesquiselenite.— ^. Terselenite.-*c. Sezselenite 247 

Iron and Iodine. 

Protiodide of Iron ..., .... .... .... 247 

Hydriodate of Ferrous Oxide .... .... 248 

lodate of Ferrous Oxide f .... .... .... 249 

lodate of Ferric Oxide. 

a. Basic lodate .... .... .... 249 

b, Biniodate .... .... .... .... 250 

Ferrous and Ferric Periodates .... .... 250 

Iron and Bromine. 

Protobromide of Iron, or Ferrous Bromide .... .... 250 

Hydrobromate of Ferrous Oxide .... .... 250 

Sesquibromide of Iron, or Ferric Bromide .... .... 250 

Hydrobromate of Ferric Oxide .... .... 251 

Ferric Oxybromide .... a.. .... .... 251 

Bromate of Ferric Oxide .... .... .... 251 

Iron and Chlorine. 

Protochloride of Iron, or Ferrous Chloride .... .... 251 

Ter-hydrated Hydrochlorate of Ferrous Oxide.... 252 

Sesquichloride of Iron, or Ferric Chloride .... .... 253 

Ter-hydrochlorate of Ferric Oxide .... .... 254 

a. Fenta-hydntted .... .... •••• 254 

k. Dodeca-hydrated .... .... .... 255 

AqaeouB Ter-hydxochloretc of Fenic Oxide .... •••• 255 



• ■ » 



CONTENTS. XZIll 

Page 
Ferric Oxychloridej or BabIc Hydrochloiato of Fenic 
Oxide. '. 

a. Soluble.... .... .... .... 265 

h, Insolable .... ,„, .... .... 256 

Perchloiute of Ferrous Oxide .... .... 266 

Iron and Flnorine. 

Protofluoride of Iron^ and Mono-hydroflnate of Ferrona 

Oxide .... .... .... .... 266 

Sesquifluoride of Iron, and Ter-hydrofluate of Ferrio Oxide 256 

Ferric Oxyflaoride, or Basic Hydrofluate of Ferric Oxide .... 257 

Iron and Nitrogen. 

Nitride of Iron .... .... .... .... 267 

Nitrate of Ferrous Oxide .... .... .... 267 

Nitrate of Ferric Oxide. 

a. Acid Nitrate .... ..^ .... 268 

6. Basic Nitrate .... .... .... .... 260 

if Azophosphate of Ferric Oxide .... .... 269 

Ferrite of Ammonia I.... .... .... .... 2G0 

Carbonate of Ferric Oxide and Ammonia .... 260 

Phosphate of Ferrous Oxide and Ammonia .... .... 260 

Phosphate of Ferric Oxide and Ammonia .... 261 

^ Ammonio-azophosphate of Ferric Oxide .... .... 261 

Sulphate of Ferrous Oxide and Ammonia .... 261 

Sulphate of Ferric Oxide and Ammonia. 

a. Basic. — b. Containing Bisulphate of Ferric Oxide. 

c. Containing Tersulphate of Ferric Oxide .... 262 
Hydrobromate of Ammonia containing Sesquibromide of 

XXuU.... .... .... ..•• .... mVM 

Ammonio-protochloride of Iron .... .... .262 

Protochloride of Iron and Anmioninm, w Ferroso-anunonic 

Chloride .... .... .... .... 263 

Ammonio-scsquichlorideof Iron. — NH^^Fe'Cl' .... 263 

Sesquichloride of Iron and Ammonium, or Ferrico-aounonio 

CWoride: 2NHK:i+Fe«Cl"+2Aq .... 263 

Sal-ammoniac containing Sesqnichloride of Iron .... 264 

Iron and Poiafisium. 

Alloy of Iron and Potaasinm .... .... .... 264 

Ferrite of Potash .... .... .... 265 

Ferrate of Potash .... .... .... .... 265 

Carbonate of Ferric Oxide and Potash .... .... 268 

Boride of Iron and Potassium .... .... .... 268 

Sulphide of Iron and Potassium .... .... 268 

Sulphate of Ferrous Oxide and Potash .... .... 268 

Sulphate of Ferric Oxide and Potash. 

a. KO,SO'+4(Fe»0»,SO»)+9Aq.: F«fliw /rofi-or» 268 

h. KO,SO'+3(2FeH)»,3SO«) + 18Aq .... 269 

c. 2(KO;30»)+Fe»0»,2SO»+6Aq .... 260 

62 



XXIV 



CONTENTS* 



I'f 



Page 

d. 2(K0,80')+8(Fe"O*^0«)-r22Aq. .... .... 269 

e. KO,SO> + Fe'0'^0'+24Aq. Poiath iron-alum 270 
Protochloride of Iron and Potassium, or Ferroso-potaBsic 

Chloride ..<... .... .... .... 271 

Sesquichloride of Iron and Potassium^ or Fenico-potassic 

Chloride *.... .... .... .... 271 

Protoilaoride of Iron and Potassium, or Ferroso-potassic 

Fluoride .... .... .... .... 271 

fiesquifluoride of Iron and Potassium, or Ferrico-potassic 

Fluoride. 

a. Terbasic: 3KF,Fe*F» b. Bibasic : 2KF,Fe*F* 271 

Iron and Sodium. 

Ferrite of Soda .... .... .... .... 271 

Carbonate of Feme Oxide and Soda .... .... 272 

Iron with Fluxes .... .... .... .... 272 

^ Pyrophosphate of Ferrous Oxide and Soda .... 272 

^ Pyrophosphate of Ferric Oxide and Soda ; .... .... 272 

Sulphide of Iron and Sodium .... 272 

Basic Sulphate of Ferric Oxide and Soda .... .... 273 

Iron and Barium. 

Alloy of Iron and Barium .... .... .... 273 

Ferrate of Baryta .... .... .... .... 273 

Sulphide of Iron and Barium .... .... 273 

Iron and Calcium. 

Hyposulphite of Ferric Oxide and lime .... .... 274 

Sulphide of Iron and Calcium .... .... 274 

Iron and Magnesium. 

Alloy of Iron and Magnesium .... .... .... 274 

Carbonate of Ferrous Oxide and Magnesia .... 274 

Sulphate of Ferroso-ferric Oxide and Magnesia: 

Botryog&M .... .... .... .... 274 

Iron and Cerium. 

Carbide of Iron and Cerium .... .... ^ 274 

Iron and Oluoinnm. 

Alloy of Iron and Glucinum .... .... .... 274 

Carbide of Iron and Glucinum .... .... 275 

Iron and Aluminum. 

Alloy of Iron and Aluminum .... .... .... 275 

Aluminate of Ferrous Oxide; Zeilaniie; Ckhrotpinelle 275 

Carbide of Iron and Aluminum .... .... 276 

Sulphate of Alumina and Ferrous Oxide: Feather-ioU, 

a. 6(FeO,SO*) + Al'0',2SO«+48Aq .... 276 

b. 2(FeO,SO')+Al«0',3SO*+27Aq.: Bergbutter 276 

c. FeO,SO« + Al"0'3SO'+24Aq. .... ... 276 



CONTENTS. XXV 

Page 

rf. MgO^O»+FeO^O*+Al»0»30»+15Aq 277 

Sulphite of Alumina and Ferric Oxide .... .... 277 

Iron and Silicium. 

Silicide of Iron .... .... ,.., 277 

Silicate of Ferrous Oxide. 

a. Disilicate: Hi/alonderite; FayaHte .... 278 

Kneheliie; FeO,MnO,8iO« .... ,.,. 279 

h. Monosilicate: Pyrwtmalite .... .... 279 

e. Six-fifths Silicate: Homeblendes rich in Iron. 

a. Arfvedstniite, — fi. Aegyrine .... .... 280 

d. Five-fourths Silicate : Krokydolite .... 281 

e, Quadrosilicate .... .... ..„ 281 

Silicate of Ferric Oxide. 

a. Monosilicate .... .... .... 281 

b, Sesquisilicate : Yellow Earth .... .... 282 

e. Bisilicate : Hisingerite .... .... 282 

d, Tersilicate: Nontronite .... .... .... 282 

e, Quadrosilicate : AnthosiderUe .... .... 283 

Silicate of Ferric Oxide with Carbonate of Soda, 

a, BihBsic: Glauber^t Iron- tree .... .... 288 

6. With 4 atoms of Acid .... .... 284 

Double Silicates containing Ferric Oxide and Alnminay on 
the one hand, and Ferrous Oxide with others of the 
stronger bases^ on the other. 

CAmnoW/tf.— 2(6Fe0^iO«) + Al*0%3SiO* + 12 Aq. .... 284 

PM-ortf. —lOFeO^iO* + Al«0»,SiO» + 6 Aq. .... 284 

Slilpnomelane.—B^FeOfiiO^ + Al'OSSSiO* + 7Aq. .... 285 

G««H/tf.— 8FeO,6SiO* + Al*0',SiO' + Aq.l .... 285 

//oai/«.— 2(2Fe0^iO«)+FeH)';3iO« 285 

Cron*<erf/i/e.— 3FeO,SiO«+Fe'0»SiO» +3Aq 286 

FrtcA/y».-3(FeO;5iO«)+Al«0»,SiO« .... .... 286 

i<cAmi/tf.— NaO^SiO' + FeO,8iO'' + Fe0^iO« .... 286 

0«re/t/tf.-^3(FeO,SiO')-|-2Al«0»^SiO«+3Aq .... 287 

ChhHte'8par.—2(FeOfiiG*) + 2Al''0»,8iO« .... 287 

I^pi(fofwfane.— <KO;FeO)SiO«H-(Fe«0»;APO^SiO'' .... 287 

i»i»^/«.— FeO,2SiO» +2(Fe«0%2SiO«)-f.l4Aq.! .... 287 

Glass-fluxes containing Ferrous and Ferric Oxide .... 288 

Carbide of Silicium and Iron .... .... 288 

Protofluoride of Iron and Silicium. — FeF^iF'.... .... 288 

Sesquifluoride of Iron and SUicium.— Fe*F"^iF' .... 288 

Iron and Titanium. 

Titanide of Iron t .... .... .... .... 289 

Titanate of Ferrous Oxide : Titan^ferout Iron. 

ct. Ilfnentte .•«. .... .... 289 

p,[ Kibdelophane .... .... .... .... 290 

y. Bamnomelane .... .... .... 291 



XXVI 



CONTENTS. 



Tiianate of Ferrio Oxide 

Biflttoride of ntammn with Sesqniflaoride of Iron..*. 

Iron and Tantalam. 
Tantalide of Iron 

Tantalite of Ferrous Oxide : a varitty qf TanioHie 
Tantalate of Ferrio Oxide. 

a, Bibasic: Columbiis,,,. «... 

b. Monobasic: Ordinary TmUaliU 

Iron and Tnngsten. 

Tnngstate of Ferrous Oxide. 

a, MonotongBtate. — Woffram 

h, Bitungstate .... 
Carbide of Tungsten and Iron 
Ferrous Sulphotungstate : FeS,WS' 
Ferric Sulphotungstate : Fe*S%3WS'.... 

Iron and Molybdenum. 

Molybdide of Iron 
Molybdate of Ferric Oxide 
Ferrous Sulphomolybdate 
Ferric Sulphomolybdate .... 
Ferrous Peisulphomolybdate 
Ferric Persulphomolybdate 

Iron and Vanadium. 

Vanadiate of Ferrous Oxide f 
Yanadiate of Ferrio Oxide. 

Iron and Chromium. 

Chromic Oxide with Fenrous Oxide : ChromeHroj^'Ore 
Chromic Oxide with Ferric Oxide 
Chromate of Ferrio Oxide. 

a. Basic. — 6. With 4 atoms of acid 
Carbide of Chromiom and Iron 

Iron and Uranium. 

Uranide of Iron f .... .... .... .. 

Iron and Manganese. 

Manganide of Iron .... .... ..«• 

^ Manganiferous Magnetic Iron-ore : (FeO,MnO)Fe'0' 
Carbide of Manganese and Iron 
Phosphate of Manganous Oxide and Ferrous Oxide. 

a. Quadrobasic: rn;>/i/«.— 4MnO;PO«+FeO,PO* ... 

b, Terbasic. 

a. rHj9*y««e.-3(T»iLiO,TSrMnO,HFeO)PO» 
/3. Tetraphyline or Ptfrot0«Artn««— 3(/,LiO,/«MgO, 
AMnO,i|FeO)PO» 



Page 
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292 



292 
292 

292 
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294 
296 
297 
297 
297 



297 
297 
297 
298 
298 
298 



298 
299 

299 
300 

300 

300 
300 
801 

301 

301 

302 



CONTENTS. xxvii 

y\ /ron-opafite.— 3MnO,PO' + 2(8FeO,PO»)FeF 302 
0. 6 atoms of Base to 2 atoms of Acid. 

a. ^tf/fpoari/e.— 5(MnO;FeO)2PO*+2Aq. .... 303 

^^- /3. -^aratt/iVtf.— 6(MnO;FeO)2PO»+8Aq 303 

Phosphate of Ferric Oxide and Manganic Oxide; Weaihergd 

Triphplinef OT Tripliie of Sodgnmais .... .... 303 

Iron aud Arsenic. 
Arsenide of Iron. 

a. Di-arsenide .... .... .... 303 

(. Mono-arsenide: Anenioal Iron or Artenieal PffrUe$ 304 

Arsenite of Ferrons Oxide .... .... 304 

Arsenite of Ferric Oxide. 

a, Quadrobasic Arsenite .... ^... .... 304 

h, Sesqni-arsenite! .... .... .... 306 

' Arseniate of Ferrons Oxide. 

a. Terbasic. — h, Bibesic .... .... .... 305 

c. Acid Salt .... .... .... 306 

Ferroso-ferric Arseniate. 

a. Cube-ore, — 6. Skorodite .... .... .... 306 

Arseniate of Ferric Oxide. 

a. Sixteen-basic. — 6, Bibasic. — o. Sesqui-arseniate 307 

Arsenio-sulphate of Ferric Oxide : Pt</tJvi/« .... .... 308 

Arseniate of Ferric Oxide and Lime : Arsenionderite 309 

Ferrous Sulpharsenite .... .... .... 309 

Ferric Sulpharsenite .... .... .... 309 

Ferrous Sulpharseniate .... .... .... 300 

Ferric Sulpharseniate .... .... .... 309 

Proto-arsenide of Iron with Bisulphide of Iron : MUpickeh 

f exvs^eo .... .... •«.. .... 909 

Iron and Antimony. 

Antimonide of Iron .... .... .... 310 

Ferrous Antimonite .... .... .... .... 310 

Ferrous Antimoniate) .... .... .... 310 

Ferrous Sulphantimonite : Berthierite or HakUnfferUe, 

a. 3FeS,2SbS\— 6. FeS^SbS'.— o. 3FeS,48bS* .... 31 . 

Ferrous Sulphantimoniate\... .... .... 311 

Antimonide of Iron and Potassimn .... .... 312 

Iron and Tellurium. 

TeUurideof Iron .... .... .... 312 

Ferrous Tellurite .... .... .... .... 312 

Ferric Tellurite .... .... ...• 312 

Ferrous Tellurate .... .... .... .... 312 

Ferric Tellurate .... .... .... 812 

Ferrous Salphotellurite .... .... .... 312 

Ferric Sulphotellurate .... .... .... 312 

Iron and Bismuth. 

Bismuthide of Iron .... .... .... 312 



xxviii CONTENTS. 

Bismntliide of Iron and PotassittiB ■• .... .... 312 

Iron and Zinc. 

Alloy of Iron and Zinc .... .... .... 312 

Ferric Oxide with Zino-oxide : FrankHniie, <— 

(ZnO;FeO),(Mn*0»;Fe«0^) •.... .... .... 313 

Carlnde of Iron and Zinc .... .... .... 314 

Sulphate of Ferrous Oxide and Zinc Oxide. 

Sulphate of Ferrous Oxide, Zinc-oxide and Ammonia .... 814 

Iron and Tin. 

Alloy of Iron and Tin .... .... .^ 314 

Carbide of Iron and Tin .... .... .... 315 

Iron and Lead. 

AUoj of Iron and Lead *.... .... .... 315 

Oilier Compounds of Iron .... .... .... 315 



Chaptke XXXIIL COBALT. 



Memoirs, Ac — ^Hiatory.— Sources. — ^Preparation 


316 


Special Modes of Separation from particular Metals. 




a. From Nickel 


.... 319 


b. From Manganese 


321 


Properties of Cobalt 


.... 322 


GoxPOViTDs OF Cobalt. 




Cobalt and Oxjgen. 




Cobalt-oxide or Cobaltous Oxide.— OoO 


322 


Hydrate of Cobalt-oxide 


.... 323 


Cobalt-salts 


324 


CobaltOBO-Cobaltic Oxide. 




a. Co»0»=6CoO,CoH)».— *. CO«0'=4CoO,Co-0' 


.... 326 


c. Co»0*«CoO,Co«0» 


326 


Cobaltio Oxide.— Co*0» 


.... 326 


Hydrate of Cobaltio Oxide 


327 


Cobaltio Salts .... 


.... 328 


Cobaltio Acid ?—CoO» 


326 


Cobalt and Carbon. 




Carbonate of Cobalt-oxide.... 


328 


Cobalt and Boron. 




Borate of Cobalt-oxide 


.... 329 


Cobalt and Phosphoms. 




Phosphide of Cobalt. 




a. With a very large excess of Cobalt 


329 


b, TriphoBphide .... 


.... 329 


Hypophosphite of Cobalt-oxide 


330 


Phosphite of Cobalt-oxide 


.... 380 



1 



CONTENTS. 

Ordinary Phosphate of Cobalt-oxide.— 2Vr6af{0 ' *... 
Pyrophosphate of Cobalt-oxide 
Y Metaphosphate of Cobalt-oxide 

Cobalt and Salphnr. 

Protosulphide of Cobalt 

Hydrosnlphate of Cobalt-oxide .... 
Oxysnlphide of Cobalt 
Seequisulphide of Cobalt : Cobalt-pyrUet 
Birolphide of Cobalt .... 
Hyposulphite of Cobalt-oxide 
Sulphite of Cobalt-oxide 
Hypoanlphate of Cobalt-oxide 
Sulphate of Cobalt-oxide. 

a. Basic Sulphate. — 6. Monosulphate : Cobali-vUriol 
Snlphocarbonate of Cobalt.... 

Cobalt and Seleninm. 

Selenide of Cobalt 

Selenite of Cobalt-oxide .... 

Seleniate of Cobalt-oxide 

Cobalt and Iodine. 

Iodide of Cobalt. — Col 

Hydriodate of Cobalt-oxide .... 
Oxy-iodide of Cobalt.— CoO,CoI ? ; .... 
Iodide of Cobalt-oxide 

Cobalt and Bromine. 

Bromide of Cobalt. — CoBr.... 

Hydrobromate of Cobalt-oxide 
Bromate of Cobalt-oxide ••«. 



...( 



■•>. 



.... 



•••» 



XXIK 

Page 
330 
331 
331 



331 
331 
322 
332 
332 
333 
3?3 
333 

333 
334 



.... 



.... 



.... 



334 
334 
334 



335 
336 
336 
336 



336 
336 
336 



.... 



336 
337 
.... 337 



337 
338 



Cobalt and Chlorine. 

Chloride of Cobalt.— CoCl 

Hydrochlorate of Cobalt-oxide .... 
% Chlorate of Cobalt-oxide 

Cobalt and Chlorine. 

Fluoride of Cobalt, and Hydrofluate of Cobalt-oxide 
Oxyfluoride of Cobalt.— 2(CoO,CoF) -|- HO .... 

Cobalt and Nitrogen, 

Nitrate of Cobalt-oxide. 

a. Sexbaaio. — b, Monobasio 
Carbonate of Cobalt-oxide and Ammonia 
Cobalto-hypoaulphate of Anmionia. — 3NH%Co*0'+ 

2(NH%S'0*) .... .... .... 339 

Ammonio-sulphate of Cobalt-oxide.— ^NH' -f CoO,SO* .... 339 

Sulphate of Cobalt-oxide and Ammonia. — NH^O,SO'-h 

CoO,SO'+6Aq .... .... 340 



.... 



338 
339 



CONTENTS, 

Page 
Ammonio-iodide of Ck>lMiU. 

a. Terbasic: 3NH*,CoI .... .... .... 340 

h, Bibasic: 2NH%Ck>I .... .... 840 

lodate of Cobalt-oxide and Ammonia .... .... 340 

Ammonio-bromide of Cobalt. — 3NH',CoBr .... 340 

Ammonio-sesquibromide of Cobalt! — 3Co*0*, 2Co*Bi* + 

16NH»+20Aq .... .... .... 341 

Cobalto-bromate of Ammonia? — NH%Co«0' + 

OCNH'^rO') + 12Aq * .... .... 341 

Ammonio-chloride of Cobalt.— 2NH%CoCI .... .... 342 

Fluoride of Cobalt and Ammoninm .m. .... 342 

Nitrate of Cobalt-oxide and Ammonia .... .... 342 

CobsJto-nitrate of Ammonia .... .... 342 

Cobalt and Poiassiam. 

Cobaltite of Potash ... .... .... .... 343 

Carbonate of Cobalt-oxide and Potash .... .... 343 

Sulphate of Cobalt-oxide and Potash .... .... 344 

Fluoride of Cobalt and Potassium .... .... 344 

Cobalt and Sodium. 

Cobaltite of Soda .... .... ...• .... 344 

Carbonate of Cobalt-oxide and Soda .... .... 344 

Cobalt with Fluxes .... .... .... .... 344 

^ ^ ^ Metaphosphate of Cobalt-oxide and Soda .... 344 

Cobalt and Calciom. 

Hypophosphate of Cobalt-oxide and Lime .... .... 344 

Cobalt and Magnesium. 

Cobaltite of Magnesia.... .... .... .... 345 

Cobalt and Aluminum. 

Aluminate of Cobalt-oxide .... .... 345 

Cobalt and Silicium. 
Silicate of Cobalt-oxide 
Hydrated Fluoride of Silicium and Cobalt 
Cobalt-glass 

Cobalt and Tungsten. 

Tungstate of Cobalt-oxide. 

a. Monotungstate. — b. Bitnngstate 
Sulphotungstate of Cobalt— CoS,WS» 

Cobalt and Molybdenum. 
Molybdate of Cobalt-oxide 
t'* Sulphomolybdate of Cobalt 

Persulphomolybdate of Cobalt 

Cobalt and Vanadium. 

Yanadiate of Cobalt-oxide. 

a. Monovanadiater- 16, Acid Yanadiata .... .... 347 



• •.. 


345 




345 


...1 


346 


• 


340 


...« 


346 




347 


.... 


347 




347 



CONTENTS. 

Page 
Cobalt and Chromiuni. 

Chromate of Ck)balt-ozide .... .... .... 347 

Cobalt and Manganese. 

Peroxide of Manganese with Protoxide of Cobalt. — Earthy 

Cobalt and Arsenic. 

Arsenide of Cobalt. ' 

a. 2 pts. Co with 3 pis. As. — h. 6(Fe;Co;Cu),As 483 

e. — Tinrwhite Cobalt, CobaMne, SmaUme, Speukobold: 

(Co;Fe;Ni)A8 .... .... .... 348 

d,-^Te8seral Pyrites: Co'As' .... .... 349 

Arsenite of Cobalt-oxide ';; ... .... .... 349 

Arseniate of Cobalt-oxide. 

a. Terbasic; Cobalt-bloom; CdbaU-coating .... 349 

h. Acid Arseniate .... .... .... 361 

Snipharsenite of Cobalt. — ^2CoSyABS' .... .... 351 

Snlpharseniate of Cobalt. — ^2CoS,A6S' .... .... 351 

Sulphide of Cobalt with Arsenide of Cobalt : CobaU-glmw, 

CoAs^CoS'^ ..„ .... .... 351 

Cobalt and Antimony. 

Antimonide of Cobalt..., 
Antimonite of Cobalt-oxide 
Antimoniate of Cobalt-oxide] 
Bnlphantimoniate of Cobalt 

Cobalt and Tellnrinm. 

Tellurite of Cobalt-oxide 
Tellurate of Cobalt-oxide .... 
Sulphotellorite of Cobalt 

Cobalt and Zinc. 

Alio J of Zinc and Cobalt .... 
Cobalt-oxide with Zino-oxide : 
Sulphate of Cobalt-oxide and Zinc-oxide 

Cobalt and Tin. 

Alloy of Cobalt and Tin .... 
Stannate of Cobalt-oxide 

Cobalt and Iron. 

AUoy of Cobalt and Iron '.... .... .... 354 

Other Compounds of Cobalt .... .... 354 



.... .... 




.... 


353 


.... 


.... 




353 


.... ...a 




.... 


35 


...I 


.... 




353 


•••t .... 




...I 


353 


»... 


.... 




353 


.... .... 




...1 


353 


.... 


.... 




853 


inman^i Green 


.... 




353 


>oxide 




.... 


354 


.*•• 


.... 




364 


.... .... 




.... 


354 



xxxu 



CONTENTS. 



••►• 



Chaptee XXXIV. NICKEL. 

Memoirs, &c., relating to Nickel 

HiBtoiy.— Sources.— Preparation .... 
Properties .... .... '"- 

CoMPouwDs OP Nickel. 

Nickel and Oxygen. 

Nickel-oxide.— NiO 

Hydrate of Nickel-oxide ' 
Nickel-salts 

Peroxide of Nickel,— Ni«0' 

Hydrated Peroxide of Nickel 

*••• •••• 

Nickel and Carbon. 

Carbide of Nickel 

•••• •••# 

Carbonate of Nickel-oxide. 

II «. Basic Carbonate: Emerald-mekel, — NiOCO'4- 
2(NiO,3HO) ,; 

h, Monocarbonate 

•••• ••.. 

Nickel and Boron. 

Borate of Nickel-oxide 



•«•« 



Nickel and Phosphorus. 
Phosphide of Nickel. 

«. Contaming but a small quantity of Phosphorus 
5. Triphosphide 

Hypophoephite of Nickel-oxide .... 
Phosphite of Nickel-oxide.... 
Phosphate of Nickel-oxide. 

a. Triphosphate. — b. Acid phosphate 
P/rophosphate of Nickel-oxide j 
IF Metaphosphate of Nickel-oxide .... 

Nickel and Sulphur; 
Bisulphide of Nickel 
Protosulphide of Nickel: Capillary PifrUet 

Hydroeulphate of Nickel-oxide 
Bisulphide of Nickel .... 

Hyposulphite of Nickel-oxide 
Sulphite of Nickel-oxide. 

«. Basic. — b, Monosulphite 
Hyposulphate of Nickel-oxide 
Sulphate of Nickel-oxide. 

a. Basic— 6. Monosulphate .... 
Sulphocarbonate 

•••• •••• 

• •>• 

Nickel and Selenium. 
Selenite of Nickel-oxide. 

fl, Monoselenite.— *. Biselenite 



P«gc 



365 

••* 3oI 



362 
363 
363 
366 
366 

366 

366 
367 

368 



368 
368 
368 
368 

369 
369 
3G9 

3G9 
370 

371 
871 
371 

372 
373 

373 
374 



374 



CONTENTS. 



XXXUl 



ft 



Seleniate of Nickel-oxide .... 

Nickel and Iodine. 
Iodide of Nickel 

Hydriodate of Nickel-oxide 
Hydrated Oxy-iodide of Nickel ! .... 
lodate of Nickel-oxide 

Nickel and Bromine. 

Bromide of Nickel 

Hydrobromate of Nickel-oxide 
Bromate of Nickel-oxide 

Nickel and Chlorine. 

Chloride of Nickel 

Hydrochlorate of Nickel-oxide 
Hydrated Oxychloride of Nickel 
Chlorate of Nickel-oxide 



•••• 



•••• 





Page 




374 


>..ff 


874 




375 


!••■ 


375 




376 


• •1. 


376 




376 


(••• 


377 




377 


• ••• 


378 




378 


• ••• 


378 



Nickel and Fluorine. 

Fluoride and Oxyfluoride of Nickel 

Nickel and Nitrogen. 

Nitride of Nickel f 
Nitrate of Nickel-oxide. 

a. Basic. — b. Mononitrate .... 
Niccolate of Ammonia 
Carbonate of Nickel-oxide and Ammonia. 

a. With excess of Carbonate of Ammonia 

b. With excess of Nickel-carbonate 
Phosphate of Nickel-oxide and Ammonia 
Hydrosulphate of Nickel-oxide and Ammonia 
Ammonio- hyposulphite of Nickel-oxide. — 2NH' + 

NiO;8»0*-f6Aq 

Ammonio-hyposolphate of Nickel-oxide. — * 3NH'-f- 

NiO,8"0» 
Ammomo-snlphate of Nickel-oxide.— 3NH*-{-NiO,80' 
Niccolo-sulphate of Ammonia.— NH*0,NiO-fNH<0,80» 
Sulphate of Nickel-oxide and Ammonia.— NH^ 0,80' -f 

NiO,80' + 6Aq 

Ammonio-iodide of Nickel. 

a. Terbasic— 3NH3,NiI .... .... .... 381 

6. Bibaeic— 2NH»,NiI .... .... 382 

Niccolo-iodate of Ammonia.— NH^Ni0 -f NH*,I0* ? 382 

Ammonio-bromide of Nickel. — 3NH*,NiBr .... 382 

Ammonio-bromate of Nickel-oxide ^ .... .... 383 

Ammonio-chloride of Nickel. — 3NH'^NiCl .... 383 

Chloride of Nickel and Ammonium.— NH^Cl^NiCl + 12Aq. 383 
Fluoride of Nickel and Ammonium .... .... 384 

Niccolo-nitrate of Ammonia.— NH»,NiO + NH^O^O* .... 384 



.... 379 



870 

.... WfV 

379 

..(. 9/9 
380 

*... 380 
380 

380 

.... 380 
381 
381 



381 



XZXIV CONTENTS. 

Page 
Nickel and Potassium. 

Niccolate of Potash .... .... .... 384 

Sulphate of Nickel-oxide and Potash .... .... 384 

{ Fluoride of Nickel and Potasflinm .... .... 385 

Nickel and Sodium. 

Niccolate of Soda .... .... .... .... 385 

Nickel-ozide with fluxes .... .... .... 385 

f Metaphosphate of Nickel-oxide and Soda .... .... 385 

Nickel, Barium, and Strontium. 

Niccolate of Bazyta and Niccolate of Strontia .... 388 

Nickel and Calcium. 

Niccolate of Lime .... .... .... 388 

Nickel and Magnesium. 

Niccolate of Magnesia .... .... .... 388 

Phosphate of Nickel-oxide and Magnesia .... .... 388 

Nickel and Aluminum. 

Aluminate of Nickel-oxide .... .... 388 

Fluoride of Aluminum and Nickel .... .... 388 

Nickel and Silicinm. 

Hydrated Fluoride of Silicium and Nickel.— NiF,8iF* -f 7 Aq. 388 
Glass-fluxes containing Nickel .... .... .... 388 

Nickel and Tungsten. 

Tungstate of Nickel-oxide.,.. .... .... 388 

a, Monotungstate. — ft. Bitungstate .... .... 388 

Sulphotungstote of Nkkel.— NiS,WB^.... .... 387 

Nickel and Molybdenum. 

Moljrbdate of Nickel-oxide .... .... .... 387 

Sulphomoljrbdate of Nickel.— NiS,MoS' .... 387 

Pennilphomolybdate of Nickel— NiSyMoS^ .... .... 387 

Nickel and Vanadium. 

Vanadiate of Nickel-oxide. 

a. Monovanadiate. — 6. Add Vanadiate .... 387 

Nickel and Chromium. 
Chromate of Nickel-oxide. 

a. Monochromate.-*^. Acid Chromate '••.. .... 387 

Nickel and Arsenic. 
Arsenide of Nickel. 

a. With very little Arsenio .... .... 388 

ft. "With 4 At. Areenic : PlaootUn^ .... .... 388 

c. Trisaraenide : Cobalhtpeim .... .... S88 



CONTENTS. XXXy 

Page 

d. Diarsenide : Copper-^nickel .... .... 389 

e. MoiuHarsemde : IVhiteNiekel'PJfrUM .... 389 

Arsenite of Nickel-oxide .... .... .... 390 

Arseniate of Nickel-oxide : Nickel-oehre .... 390 

Bisulphide of Nickel with Proto-arsenide of Nickel: 

Nickel-glance .... .... .... 391 

Sulpharsenite of Nickel.— 2NiS,A8S' .... .... 892 

Sulpharseniate of Nickel.— ^NiS^AsS', and 2NiS^S» ..,. 392 

Nickel and Antimony. 

Antimonide of Nickel : AntitMnidl Nickel .... 392 

Antimoniate of Nickel-oxide .... .... .... 393 

Bisulphide of Nickel with Antimonide of Nickel; 

Nickel{ferou$ grey Antimonyj HartmannU$ .... 393 

Bulphantimoniate of Nickel.— 3NiS^SbS* .... .... 393 

Nickel and Tellarium. 

Tellurite of Nickel-oxide .... .... .,.. 393 

Tellurate of Nickel-oxide .... .... .... 393 

Sulphotellurate of Nickel .... «... .... 393 

Nickel and BismntL 

Alloy of Nickel and Bismuth .... .... .... 393 

Sulphide of Bismuth and Nickel : NkkehUmuthrglmoe 393 

Nickel and Zinc. 

Alloy of Nickel and Zinc .... .... .... 394 

Sulphate of Nickel-oxide and Zinc-oxide .... 394 

Nickel and Tin. 

Alloy of Nickel and Tin .... .... .... 394 

Nickel and Lead. ' 

AUoy of Nickel and Lead .... .... .... 394 

Plumbite of Nickel-oxide .... .... .... 394 

Nickel and Iron. 

Alloys of Nickel and Lron .... .... .... 394 

Meteoric Iron .... .... .... .... 395 

Niccolate of Ferrous Oxide, and Ferrite of Nickel-oxide 396 

Carbide of Nickel and Iron .... .... .... 396 

Sulphide of Nickel and Iron : Iron-nickel Pyritee .... 396 

Sulphate of Nickel-oxide and Ferrous Oxide .... .... 397 

Nickel and Cobalt. 

Alloy of Nickel and Cobalt .... .... 397 

Other Componnds of Nickel .... .... .... 397 



CHArizft XXXr. COPPER. 



Memoin.&c. — Hiatoij. — Bonrce*- .... 

PrepAlmUou 

Propertiea .... 

CoHPoDirits OP CoFPZB. 
Copper and Oxgyea 

CnproM Oxide.— Cn*0 .... 

Hjdrate of Cnpnma Oxide .... 

Cuprooa Salts {.... 

Capiio Oxide. — CnO .... 

Hj'dnte of Cupric Oxide .... 

Capric Salts 
Peroxide of Copper! .... .,.. .... 

\ CnpricAcidI 

Copper and Hydrogen. 
Hydride of Copper? 

Copper and Carbon. 

CulHde of Copper .... .... „„ 

Cubaiute of Cupric Oxide. 
a. VicarbODftte. 

a. Anhjdcaiu : MfmSiu .... 

^. HjdnM: MmImcUu 

h. Seaqmcwbonate .... 
«. Add OBrbonete 

Copper and Boron. 

Borate of Cnpria Oxide .... 

Copper and Plioephorns. 

Phoephida of Copper.— «. Cu'P ... 

t, Triphosphide 

e. Diphoephids .... 
HTpopboaphite of Cnpric Oxide f.... 
Phoiphite of Cupric Oxide 
Phoapliate of Cnpric Oxide. 

a. Sexbanc 

b. Qaintobeaie : PtiotpkonealmU or P$eude-atalaeAitt ... 

e. QuadrolMac : Liibelhtnilt 
d. Terbasio 

«. Bibamc : TyombolUt 

f. Acid Phosphate 
PyrophoBphate of Cupric Oxide 

•{T Met^hoophats of Capric Oxide .... 



J 



CONTENTS. XXXvii 

Copper and Sulphur. 

"Disalphide of Ck)ppeT : Copper-glanoe .... .... 422 

Protosulphide of Copper : Indigo Coj>per, Blue Copper, or 

BreithaupHte .... ..., 422 

Pentasulphide of Copper .... ..,, 422 

Hyposulphite of Cuprous Oxide .... ... .... 423 

Sulphite of Cuprous Oxide .... .... 423 

Sulphite of Oupric Oxide .... .... ... 424 

Hyposulphate of Cupric Oxide. 

a. Quadrobasic .... .... .... 424 

6. Monobasic .... .... ... ., 425 

Sulphate of Cupric Oxide. 

a. Octobasic. — b, Quadrobasic: BrochanHte .... 426 

e. Dibasic? .... .... .... . 426 

d. Monobasic: Sulphate of Copper, Blue Vitriol 427 

a. Mooo-hydrated. — p. Bi-hydratcd. — y. Fenta-hydrated 430 

Carbosulphide of Copper? .... .... .. 43Q 

Sulphocarbonate of Copper ... .... .. 431 

Cuprous Hyposulphophosphite. 

a. Dibasic: 2Cu''8,P8.- 6. Monobasic : Cu*8,PS 431 

Cupric Hyposulphophosphite.— CuSJPS .... .... 431 

Cuprous Sulphophosphite.— 2Cu'S,P8' .... 431 

Capric Sulphophosphate. 

a. Octobasic: 8CuS,PS*.— A. Dibasic: 2Cu8^S* .... 432 

Copper and Selenium. 

Diselenide of Copper, or Cuprous Selenide .... 432 

Protoselenide of Copper, or Cupric Selenide .... .... 432 

Selenite of Cuprous Oxide ... .... .... 432 

Selenite of Cupric Oxide. 

a, Dasic— 6. Monoselenite .... .... 433 

Seleniate of Cupric Oxide .... .... . 433 

Copper and Iodine. 

Diniodide of Copper, or Cuprous Iodide .... 433 

lodate of Cupric Oxide .... .... 434 

Periodateof Cupric Oxide.... .... ... 434 

Copper and Dromine. 

Dibromide of Copper, or Cuprous Dromide .... 435 

Hydrobromate of Cuprous Oxide .... .... 43© 

Hydrobronuite of Cuproeo-cupric Oxide .... ..„ 43^ 

Protobromide of Copper, w Cupric Droznide .... 435 

Hydrobromate of Cupric Oxide ..,. ... 43^^ 

Cupric Oxybromide, and Dasic Hydrobromate of Cupric 

Oxide .... .... ... 43g 

Dromate of Cupric Oxide. — a. Sexbasic .... 437 

b. Monobasic ..,. .... ... 433 



XXXVIU 



CONTENTS. 



Page 

Copper and Chlorine. 

Oichloride of Copper, or CnprouB Chloride .... .... 438 

Add Hydrochlorate of Caprous Oxide.... .... 439 

Copric Oxide with Cuprous Chloride.— Cu'Cl,2CuO .... 438 

Aqueous Cuproeo-cupric Chloride^ or Hydrocblorate of 

CuproBO-cupric Oxide.... .... .... 438 

Protochloride of Copper, or Cupric Chloride .... .... 438 

Hydrated Protochloride of Copper, or Mono-hydro- 

chlorate of Cuprio Oxide .... .... 439 

Cupric Oxychloride. 

a, CnCl,2CnO .... .... .... .... 440 

b. CuCl,3CuO.— Hydrated: Atakamile .... 441 
0. CnCl,4CnO g' .... .... .... .... 442 

Hypochlorite of Cupric Oxide .... .... 442 

Chlorate of Cupric Oxide] .... .... .... 442 

Perchlorate of Cupric Oxide .... .... 442 

Copper and Fluorine. 

Difluoride of Copper, or Cuprous Fluoride .... .... 442 

Protofluoride of Copper, and Monobasic Hydrofloate of 

Cupric Oxide .... .... .... 443 

Hydrated Cuprio Oxyfluoride, or Bibasic Hydrofluate of 

Cupric Oxide .... .... .... .... 443 

Borofluoride of Copper. — CuF,BF» .... .... 443 

Copper and Nitrogen. 

Nitride of Copper. 

a. With very great excess of Copper .... .... 444 

b. Somewhat richer in Nitrogen ? .... .... 444 

0. Cu N .... .... .... .... 444 

Nitrite of Cupric Oxide .... .... .... 446 

Nitrate of Cupric Oxide. 

a. Terbasic— 6. Monobasic .... 446 

Cuprous Oxide with Ammonia .... .... .. . 447 

Cupric Oxide with Ammonia .... .... 447 

Carbonate of Cupric Oxide with Ammonia .... .... 448 

Boride of Nitrogen and Copper ? .... .... 448 

Cupro-hyposulphate of Ammonia .... .... .... 448 

Ammonio-Bulphate of Cupric Oxide. — 5NH*-f 2(CuO,SO') 448 

Cupro-sulphate of Ammonia.— NH",CnO + 2NHH),SO' .... 449 

Bibasic-sulphate of Cupric Oxide and Ammonia. — 

NH%CuO,80» .... .... .... 450 

Sesquibasic Sulphate of Cupric Oxide and Ammonia.— 

^H*,2CuO,2SO».... .... .... ... 450 

Monobasic Sulphate of Cupric Oxide and Ammonia. — 

NHK),80»-|-CuO,80»-f6Aq .... 450 

Ammonio-diniodide of Copper.— 2NH»,Cu'I ... .... 450 

Ammonio-protiodide of Copper. — ^2NH",CttI + Aq 451 

Cupro-iodate of Ammonia .... .... .... 452 

Ammonio-dibromide of Copper .... .... 462 



CONTENTS. xxxix 

Ammonio-protobromide of Copper. 

a. 5NH»,2CuBr.-6. 3NH%2CuBr ... .... 462 

Cupro-bromate of Ammonia.— NH*,CuO + NH^BrO* 452 

Ammonio-dichloride of Copper .... .... .... 453 

Dichloride of Copper and Ammonium : Cuproto-ammome 

Ammonio-protochloride of Copper. 

a. With 3 At. Ammonia.— 3NH",CuCl .... .... 453 

h. With 2 At. Ammonia.— 2NH',CuCl+H0 or 

NH»,CuO+NH«,HCl ... .... 453 

0. With 1 At. Ammonia.— NH'jCua .... .... 464 

Protochloride of Copper and Ammonium: Cuprico-ammonie 
Chhride, 

a. NH*Cl,CuCl + 2Aq. .... ... 454 

If b. NH*a^CnCl+4Aq .... .... 455 

Cupro-nitrate of Ammonia.... .... .... 465 

IT Azophosphate of Cupric Oxide .... .... .... 456 

Copper and Potassiam. 

Alloy of Copper and PotaflBinm .... ... 456 

Cuprous Oxide with Potash .... .... .... 456 

Cupric Oxide with Potash .... .... .... 45? 

Carbonate of Cupric Oxide and Potash .... .... 458 

Sulphide of Copper and Potassium .... .... 458 

Hyposulphite of Cuprous Oxide and Potash. 

a. K0^*0« + CuH),8«0«+2Aq. .... ... 468 

6. 3(KO;3«0«)+Cu«0;8»0«+3Aq. .... 459 

Sulphite of Cuprous Oxide and Potash .... .... 459 

Sulphate of Cupric Oxide and Potash .... .... 469 

Seleniate of Cupric Oxide and Potash .... .... 460 

Diniodide of Copper and Potassium : CuprtMhpottugie 

Iodide .... .... .... .... 460 

Dichloride of Copper and Potassium : Cupr^fo-^taesie 

Chloride .... .... .... .... 460 

Protochloride of Copper and Potassium : Cuprioo-potaaie 

Chloride .... .... .... .... 460 

Fluoride of Copper and Potassium .... .... 401 

Copper and Sodinm. 

Cupric Oxide with Soda .... .... .... 461 

Carbonate of Cupric Oxide and Soda .... .... 461 

Copper with Fluxes .... .... .... 461 

Hyposulphite of Cuprous Oxide and Soda. 

a. 2(NaO,SH)") + 3(Ctt'*0,8«0')+5Aq ... 461 

b. 3(NaO,S«0') + Cu«0,S»0»+2Aq. .... 462 

Sulphate of Cupric Oxide and Soda .... .... 4 62 

Dichloride of Copper and Sodium : Cuproso-sodic Chloride 462 

Copper and Barium. 

Alloy of Copper and Barium ! .... .... .... 462 

c2 



Zly 



x\ CONTENTS. 

Page 
Cupric Oxide with Baryta ? .... .... 463 

Sulphide of Copper and Barium .... .... .... 463 

Dichloride of Copper and Barium : Cuprotobaryiic Chloride 463 

Copper and Calciam. 

Cupric Oxide with lime .... ... .... 463 

Sulphide of Copper and Calcium .... .... 463 

Cupric Sulphate with Fluoride of Calcium .... .... 463 

Copper and Magnesium. 

Sulphide of Copper and Magnesium .... .... 463 

Sulphate of Cupric Oxide and Magnesia .... .... 463 

Sulphate of Cupric Oxide^ Magnesia, and Ammonia 40*3 

Copper and Aluminum. 

Aluminate of Cupric Oxide .... .... .... 464 

Fluoride of Aluminum and Copper .... 464 

Copper and Zirconinm. 

Zirconate of Cupric Oxide .... .... .... 464 

Copper and Silicinm. 

Silicide of Copper .... .... .... 464 

Silicate of Cupric Oxide, 
a. Bfonosilicate. 

a, Mono-hydrated : Emerald-copper or Dioptase .... 464 

/3. Bi-hydrated: Chrysoeolla.... .... 465 

6. Quadroeilicate.... .... .... .... 465 

Cuprous Silicofluoride.— Cu'F,SiF* .... .... 465 

Cupric Silicofluoride.—CuF,8iF*+ 7 Aq .... 466 

Cuprous Oxide with Glass-fluxes .... .... 466 

Copper and Titanium. 

Hydrated Fluoride of Titanium and Copper .... .... 466 

Copper and Tungsten. 

Alloy of Copper and Tungsten .... .... 466 

Tungstate of Cupric Oxide. 

a, Monotungstate. — 6. Bitungstate .... .... 466 

Sulphotungstate of Copper.— CuSjWS" .... 466 

Copper and Molybdenum. 

Alloy of Copper and Molybdenum .... .... 467 

Molybdate of Cupric Oxide .... .... 467 

Sulphomolybdate of Copper. — CuS,MoS' .... .... 467 

Persulphomolybdate of Copper. — CuS, MOS * .... 467 

Copper and Vanadium. 

Yanadiato of Cupric Oxide. 

a. Monovanadiate. — b, Bivanadiate .... 467 

Copper and Chromium. 

Chromate of Cupric Oxide. 

a. Polybasic? .... . . .... ... 4^7 

b, Basic! — c. Monochromate .... ^.. 468 



CONTENTS. xli 

Page 

Chromate of Cuprio Oxide and Ammonia .... 468 

Copper and Uranium. 

Pboq>hate of Uranic Oxide and Gnpric Oxide : ChaikolUe .... 468 

Copper and Manganese. 

Alloy of Copper and Manganese .... .... 468 

Peroxide of Manganese with Cupric Oxide: Cupreous 

Manganese .... .... .... .... 468 

Permanganate of Cupric Oxide .... .... 468 

Copper and Arsenic. 
Arsenide of Copper. 

a. Containing but a small quantity of Copper .... 470 

b. Cu*F.—o. Cu'P .... .... .... 470 

Arsenite of Cupric Oxide. 

a. Mono-arsenite I SeheeWs Green .... .... 470 

6. Acid Arsenite .... .... .... 470 

Arseniate of Cupric Oxide. 

a. Octobasic! Copper-miea .... .... .... 471 

b. Pentabasic. 

a. Bi-hydrated : Ertniie .... .... 471 

/9. Penta-hydrated : Ajhanese .... .... 471 

y. Deca-hydrated : Leiroehr&ite .... 472 

c. Quadrobasic. 

a. Mono-hydrated : O&vemte.... .... 472 

/3. Heptarhydrated : Euehroite .... .... 473 

y. Deca-hydrated : Liroeonite .... 473 

d. Terbasic .... .... .... .... 473 

Cupric Sulphareenite. 

a. 12CuS,Afl8».— 6. 3Ctt8,A8S* .... .... 474 

c. 2GuS,A8S' .... .... .... .... 474 

Cupric Sulpharseniate. — ^20nS,As8* .... .... 474 

Copper and Antimony. 

Antimonide of Copper .... .... .... 474 

Antimonio Oxide with Cuprous Oxide.... .... 474 

Antimonite of Cupric Oxide .... .... .... 475 

Antimoniate of Cupric Oxide .... .... 475 

Cuprous Sulphantimonite : AnHm<mial Copper-glance. — 

Cu?S,8b8» .... .... .... 476 

Cupric Sulpbantimoniate. — 3CuS,Sb8^ .... .... 476 

Antimonide of Copper and Potassium .... ... 476 

Copper and Tellnriani. 

Telluride of Copper .... .... .... 477 

Tellurite of Cupric Oxide .... .... .... 477 

TeUurate of Cupric Oxide .... .... .... 477 

Sulphotellurite of Copper,— 3CuS,TeS* .... .... 477 

Copper and Bismuth. 

Alloy of Bismuth and Copper .... .... 477 

Sulphide of Bismuth and Copper : Copper-bumuih-glanee .... 477 



xlii CONTENTS. 

Page 
Copper and Zioc. 

AUoyB of Copper and Zinc .... .... ... 477 

m Tombac, Pinchbeek, Ac. .... .... 479 

6« BnaB. — ft Mosaic Gold. — d. Brazier^ Solder .... 480 

Carbonate of Cnpric Oxide and Zinc-oxide : AuHchaldUe 480 

Sulphate of Cupric Oxide, Zino-oxide, and Potash .... 481 

Copper and Cadminm. 

AUoy of Copper and Cadmium .... .... 481 

Copper and Tin. 

Alloys of Copper and Tin : Brofute, Gun-^itetaij Bell- 

meialf &c« .... .... .... .... 481 

Stannate of Caprona Oxide .... .... .... 483 

Stannate of Cnpric Oxide .... .... .... 484 

Copper and Lead. 

Alloy of Copper and Lead .... .... .... 484 

Cnproua Oxide with Lead-oxide .... .... .... 484 

Cnpric Oxide with Lead-oxide .... .... 486 

Sulphide of Copper and Lead .... .... .... 486 

Hyposulphite of Cupric Oxide and Lead-oxide I .... 486 

Selenide of Copper and Lead. 

a, 4PbSe,CuSe .... .... .... .... 486 

b. 2PbSe,CuSe : Sslenkupferblei .... .... 486 

0, Vhae,CuQe : SelefMeiiufifer .... .... 488 

Chromate of Cupric Oxide and Lead-oxide: Vaugueliniie 486 

Antimonide of Copper and Lead .... .... 487 

Sulphide of Antimony, Copper, and Lead* 

a. Boumoniie .... .... .... .... 487 

b, Pfitmaioidal Copper-glance .... .... 488 

Sulphide of Bismuth, Copper^ and Lead : Needle-ore .... 488 

Alloy of Copper, Lead, Tin, and Zinc .... .... 488 

Copper and Iron. 

Alloy of Copper and Iron .... .... .... 489 

Carbide of Copper and Iron .... .... 489 

Sulphide of Copper and Iron. 

a. Purplfi Copper, PhUHptine.... .... < .... 489 

b, Copper-pjfriies .... .... .... 491 

Sulphate of Cupric Oxide and Ferrous Oxide ; Ferroeo- 

cuprie Sulphate .... .... .... 492 

Sulphantimoniate of Copper and Iron : Fahl-cre or Grey 

Copper .... .... .... .... 492 

a. Tennantiie .... .... .... 492 

/9. Light grey Copper. — y. Dark grey Copper .... 493 

d. Silver Fahl-ore.-^, QuiokHltfer Fahl-ore .... 494 

Alloy of Copper, Iron, and Zinc .... .... .... 496 

Sulphosiannate of Iron and Copper : Tin-pyrites .... 496 



iS^ 



CONTENTS. xliii 

Page 
Copper and Cobalt. 

Sulphate of Capric Oxide and Cobalt-oxide : Cobaltwo- 

euprio Suiphaie .... .... .... .... 496 

Copper and Nickel. 

Alloy of Nickel and Copper .... .... .... 497 

Sulphate of Cupric Oxide and Nickel-oxide .... 497 

Sulphate of Cupric Ozdde, Nickel-oxide, and Potash .... 497 

Alloy of Copper, Nickel^ and Zinc : Nickel-siiver, German 

Stiver, White Copper, Paeitfang .... .... 497 

Other Compounds of Copper .... .... .... 499 



METALS, 

(Contimied.) 



CnAPTER XXVIII. 

ZINC. 



Berffman. De mineris Zinci. Opmc. 2, 209. 

De Lassonne. Crell. Chem. Joum. 3, 165, and 5, 59. 

A. Vogel. Schw. 11, 408. 

Schindler. Mag. Pharm, 31, 167; 36, 43. 

Wackenroder. Ann. Pharm. 10, 63; 11, 151; 42, 348. — iT. Br. Arch. 

16, 133. 
Kane. Ann. Chim. Phys, 72, 290. 



Synontmes. Spelter^ Spiauter, ZinJc, Zincum. 

History. The ere of zino called Calamine, or Cadmia, — ^but not the 
pure metal — was known to the ancient Greeks and nsed in the nianu- 
ractare of brass. The metal zinc was first mentioned by Paracelsus; it 
was for a long time imported from the East, but since the middle of the 
eighteenth century, it has been prepared in Europe. 

Sources. Kb oxide; as carbonate; as sulphide; as sulphate; as 
aluminate; as silicate; as a compound of ferric oxide with zinc-oxide; 
and as a double carbonate of copper and zinc. 

Preparation. Native carbonate or silicate of zinc-oxide, freed by 
previous roasting from carbonic acid and water— or zinc-oxide obtained by 
prolonged roasting from the native sulphide — or zinc-oxide which has 
sublimed in the upper part of the furnace-shaft during the fusion of other 
ores, is mixed with about \ of its weight of charcoal-powder, and heated 
to a low white heat in retorts or retort-like vessels of earthenware or 
iron: the zinc is then reduced and volatilized, and condenses in the colder 
part of the apparatus. In Silesia, the mixture of zinc-oxide and charcoal 
or coke is heated in muffles 3 feet long and 1^ foot high, six of which 
(three side by side) are laid in one furnace. The evolved mixture of 
carbonic oxide gas and zinc vapour passes from the npper and fore part 
of the muffles, through a knee-shaped channel, horizontal in the nearer 
and directed downwards in the farther part, and the zinc condenses 

. VOL. V. B 



2 ZINC. 

Hiereiii and drops down from its lower aperture. Part of the zinc 
vapour, and likewise some cadmium vapour, escapes un condensed together 
with the carbonic oxide gas, and burns in the air, producing the substance 
called SiUHan Zinc-flowers, {Schlesitche Zinhhlumen.) In Liege, the 
reduction is performed in earthenware tubes, laid side by side. The zinc, 
as it condenses in the fore part of these tubes, is scraped out from time 
to time in the liquid state. In England, a number of cast-iron pots are 
arranged in a circle in one common furnace. Through the bottom of 
each of these pots there passes a tube open at both ends. The vessels 
are filled with the mixture to such a height as not to stop up the upper 
end of the tube, then closed with a well-fitting cover, and heated. The 
zinc drops down from the part of the tube which descends from the 
bottom of the crucible. This process \sciaX[e^De8till<Uioper descensum,^^ 
2. At Goslar, zinc is obtained as a secondary product in the smelting of 
lead ores. The zinc vapours condense in the upper half of the furnace, 
and run down from the shaft upon a slanting stone called the zinc-stooL 
(Zinksttihl.) The zinc thus obtained is melted in iron pots and poured 
out on tables. 

Commercial zinc may contain charcoal, sulphur, manganese, arsenic, 
antimony, cadmium, tin, lead, iron, cobalt, nickel, and copper. Uranium 
has likewise been mentioned as an impurity in zinc, but probably copper 
was mistaken for it. Carbon is contained in zinc in the form of charcoal 

Splinters, according to Wackenroder, and as carbide of zinc, according to 
ren, Berzelius, and Schindler. East Indian zinc contains only 0*43 per 
cent, of lead and 0*24 of iron. (Bonnet.) Silesian zinc contains a large 
quantity of cadmium, besides charcoal, lead, iron, and a very small 
quantity of copper. (Wackenroder, Jansen.) Houton Labillardiere and 
6. Barruel {CompL rend. 14, 724; also J, pr. Ckem, 26, 383) found tin 
in several sorts of zinc. Three samples of East Indian zinc were found 
by Wittstein {Repcrt, 55, 193) to give the results a, 6, c; rf is an analysis 
by Jacquelain {Compt rend, 14, 636; also J. pr. Chem. 26, 298) of a 
sample of unknown origin. 





a. 




h. 




e. 




d. 


Zn 


96-27 




9905 




98-76 




99-170 


Pb 


3-33 




0-27 




0-91 




0-685 


Cd 


0-30 




0*23 




0*16 






Fe 


0-10 




trace 




017 




0'142 


C 














0003 



10000 .... 99-55 .... 100-00 .... 100000 

Commercial zinc, when dissolved in dilute sulphuric acid, leaves a 
black powder. In Silesian zinc, this residue amounts to 2 per cent., and 
oonsists of sulphide of lead and charcoal splinters. (Wackenroder.) 
A. Yogel found in this black powder, carbon, sulphur, lead, and iron ; 
Jacquelain found carbon, lead, and iron: he likewise obtained the same 
residue, but containing less lead, by distilling zinc in a stream of 
hydrogen. G. Barruel, by reducing in a charcoal crucible the powder 
which remained after dissolving zinc in dilute sulphuric acid, obtained an 
alloy containing 58*6 p.c. tin, 34*5 lead, 5'5 sulphur, with traces of iron 
and manganese. 

Purifieaiion. 1. The zinc is distiUed once or twice either in an 
earthen retort (the neck of which, however, is soon stopped up by the 
sublimed zinc), or else in an earthen or iron crucible, into the bottom of 



«INC. 3 

which is luted a tube open at both ends and reaching nearly to the top; 
the mouth of the crucible is stopped with a well-fitting cover. — Witts tein 
{Repert. 61^ 220) introduces into an uncoated Hessian retort, capable of 
holding from 24 to 30 ounces of water^ 4 pounds of comminuted ziucy 
heats it gradually in a wind-furnace covered with a dome six feet high — 
and, when the distillation has begun, which takes place after an hour or 
an hour and a half, and the zinc condenses in the neck of the retort, 
scrapes it out with a curved iron wire, while still liouid, into a basin 
containing water and placed below to receive it. If tne scraping be not 
assiduously kept up, the neck becomes stopped up with solid zinc; if the 
neck is too short, some of the zinc burns away. This process yields about 
8^ pounds of zinc, still containing cadmium; a greenish yellow powder 
remains in the retort. — Jacquelain (N. Aim. Chim. Phys, 7, 199) distils 
the zinc in a current of hydrogen. The hydrogen is evolved in a 
Woulfe's bottle from purified sulphuric acid, zmc, and water, and made 
to pass, first through solution of potash, then through two chloride of 
calcium tubes, then into a red-hot porcelain tube, in which are placed 
little boats or dishes of porcelain containing the zinc to be purified, and 
lastly through a knee-shaped tube into oil of vitriol. The zinc is 
deposited in the colder part of the porcelain tube (antimony and cadmium 
may be distilled in a similar manner). — Distillation, however, does not 
purify the zinc completely, especially from the more volatile metals, such 
as cadmium and lead; according to Berzelius and Dulong {Ann. Chim* 
Phys. 15, 888), the zinc after distillation contains the same impurities as 
before. 

2. Sulphur, either alone or mixed with grease, is repeatedly stirred 
about with a stick at the bottom of melted zinc, in order to convert the 
foreign metals into sulphides. The more briskly the sulphur is stirred 
about, the more complete is the purification: the process, however, does 
not remove the whole of the lead and iron. (Bonnet, Schwake, Ann, 
Pharm. 9, 184.) 

3. Commercial zinc fused and very hot is poured into a deep bucket 
filled with water, in order to granulate it as finely as possible; 1 part of 
this granulated zinc is then placed, together with \ pt. nitre, in a crucible, 
in such a manner that there may be a small portion of free nitre both at 
top and bottom, and the whole is heated in the furnace till vivid com- 
bustion ensues. The crucible is then taken out, the slag removed, and 
the zinc poured out. The zinc thus treated is free from arsenic and iron. 
(Maillet, /, Pharm, 27, 625.) 

4. To obtain perfectly pure zinc, it is necessary to distil perfectly 
pure zinc-oxide with lamp-black (or charcoal) in a retort, and free the 
product from any charcoal that may be mixed with it, by a second 
distillation: but this distillation, on the small scale, is attended with many 
difficulties. 

Testing, The hydrogen gas evolved on dissolving the zinc in pure 
dilute sulphuric acid should ^ive no precipitate when passed through 
solutions of lead, silver, or gold salts; a precipitate would indicate the 
presence of sulphur or arsenic; it must neither yield arsenic spots, nor 
deposit metallic arsenic when passed through a red-hot tube (IV. 268); 
fuming nitric acid through which the gas has been passed ought to 
evaporate completely over the water-bath : sulphur, arsenic, or antimony 
would remain behind in the form of an acid.—- The zinc when dissolved 
in dilute sulphuric acid must leave no residue. The resulting solution of 

B 2 



4 ZINC. 

ziDO-sulpbate, when sapersatarated with sulpharic acid^ must give no 
precipitate with sulphuretted hydrogen (cadmittm, copper, tin); metallic 
zinc immersed in it should produce no metallic deposit (cadmium, tin, 
copper). The precipitate which potash produces in the solution of the 
sulphate should be perfectly soluble in excess of the re-agent (the oxides 
of iron, copper, and cadmium would be left undissolved). The solution 
of the zinc in aqua-regia should give no precipitate with chloride of 
barium, — ^that is to say, it must be free from sulpnuric acid. 

Properties. Crystallizes in long, regular, six-sided prisms. (Nogge- 
rath, Pogg. 39, 324.) According to former statements, it crystallizes in 
four-sided prisms and needles. Zinc containing from 3 to 4 per cent, of 
iron was found by Laurent and Holms {Ann, Ckim. Phys. 60, 333) in the 
cracks of the earthen tubes in which it had been distilled, crystallized 
in rhombic prisms. IT. Nickles {N, Ann, Chim, Phys, 22, 37) states 
that zinc prepared by Jacquelain's method of distillation in a current of 
hydrogen, crystallizes in well-defined pentagonal dodecahedrons : henoe 
it is dimorphous. % Zinc has a broadly laminar texture. It is mode- 
rately hard, difficult to file, and when bent after fusion, emits a crack- 
ling noise, but not so loud as tin. If hammered with great violence, it 
splits in the direction of the cleavage-planes ; but by careful pressure^ 
whereby it loses its crystalline structure, it may be rendered ductile, and 
may then be extended into thin plates or wires. According to Hobson 
and Sylvester {GUb. 24, 1 04), it exhibits its greatest degree of ductility 
and malleability at temperatures between 100*^ and 150^ ; at 205°, on 
the contrary, it is so brittle that it may be pounded in a mortar. Hence, 
to obtain zinc-plate, or zinc-foil, the metal cast in a tabular form is 
heated in a boiling solution of common salt, and then passed between 
rollers. To obtain pulverized zinc, on the other hand, the melted metal 
is poured into a strongly heated crucible, and the heated mass strongly 
rubbed and stirred with an iron pestle till it solidifies. (Bottger, Ann, 
Pkarm, 34, 85.) — The specific gravity of commercial zinc solidified after 
fusion is 6'861 (Brisson); of purified zinc, 6*9154 (Karsten); of rolled 
commercial zinc, 7'1908 (Brisson). Zinc has a bluish grey-white colour, 
and a strong lustre. Fuses at 260'' (Black), at 374'' (Morveau), at 412'' 

i'Daniell), and boils at a white heat. Contracts strongly in solidifying 
rom fusion (Marx). 

Atomic Weight, 32-26, Berzelius; 3309, Jacquelain; 33, Favre 
(Ann. Pharm. 48, 193). 



Compounds of Zinc. 
Zmc AND Oxygen. 

A* Svth'Oxide of Zinc 9 

Zinc exposed to the air at ordinary temperatures, becomes covered 
with a thin grey film, which prevents the further oxidation of the inner 
portions. Zinc heated just to the melting point, oxidates still more 
rapidly, and forms a grey powder, which, however, is soon converted 
into the white oxide. Berzelius regards this grey substance as a sub- 
oxide ; Proust, Davy, and A. Yogel regard it as a mixture of the metal 
and the oxide. 



ZINC-OXIDE. 



B. ZiKC-oxiDE. ZnO. 



Oxide of zinc, Protoxide of tine, Zinioxyd, Oxyde nncique. — Bed zinc- 
ore IS a mixture of S8 parte zinc-oxide aud 12 parts maDganoso-manganic 
oxide. 

Formation, Zinc heated to redness in the air bums with a dazzling 
bluish and greenish flame, and forms zinc-oxide, which partly remains in 
the crucible, partly rises up in the air, and falls down again in large 
flakes — Flowers of zinc, Zinhblumen, Flores zind^ Lana philogophica, 
NihUum album. When it has once taken fire, it continues to burn, even 
after the crucible has been removed from the furnace, till the whole is 
converted into oxide, provided it be constantly stirred and the oxide 
removed as it forms. (Sementini.) Zinc heated in the air iust to the 
melting point, is m^ually converted, first into sub-oxide and then into 
oxide. — 2. At ordinary temperatures, zinc remains bright in dry air. If 
water be present, the hydrated oxide is formed; and if the air likewise 
contains carbonic acid, hydrated basic carbonate of zinc is produced. 
Zinc placed under a receiver surrounded at the bottom with water and 
contaming air free from carbonic acid, becomes covered with drops of 
moisture, and tarnished on the surface by the formation of a whitish-grey 
film of hydrated oxide. But if a piece of tarnished lead be placed under 
the same receiver, though not in contact with the zinc, the drops of water 
are deposited only on the lead, not on the zinc, which therefore remains 
bright. Under water which is in contact with air free from carbonic acid, 
zinc becomes covered with hydrated oxide containing 7 per cent, of water. 
Zinc exposed to moist air containing carbonic acid, — to the open air, for 
example, — becomes covered with hydrated basic carbonate of zinc. The 
same salt is formed when zinc is exposed to the air under water. (Vou 
Bonsdorff, Pogg. 42, 325.) When zinc is exposed to the air, under water 
containing -^^ of hydrate of potash, it turns grey, and forms white shining 
laminiB of carbonate of zinc : no zinc is dissolved in the water. (A. Vogel, 
J, pr. Chem, 14, 107.) — The following remarkable observations of Bons- 
dorfi* may likewise be added in this place. Whenever two metals are 
placed — not in contact with each other — under a bell-jar containing air 
and closed at the bottom with water, only the more oxidable metal is 
bedewed, and therefore oxidated : e,g, arsenic or lead placed in a moist 
atmosphere near copper or silver. Copper or silver placed alone under 
the bell-jar condenses the dew on its surface. The contrary effect takes 
place if the metals are in contact : thus, when copper is in contact with 
zinc, the copper alone is bedewed; when copper is in contact with silver, 
the condensation of moisture takes place only on the silver. — Zinc* does 
not decompose pure water at ordinary temperatures; but«kt a red heat 
or in presence of acids or alkalis, the decomposition takes place. Zino 
sealed up in a glass tube together with water deprived of air by boiling, 
remains bright for years. (Bonsdorff, Boutigny, Ann. de Hyg, publ. 17, 
290.) It does not decompose pure water, even on boiling; and even 
when placed in contact with copper, it does not decompose pure water, 
but only water containing a salt. (J. Davy, N, Ed. Phil, J. 17, 47.) When 
vapour of water is passed over zinc at a low red heat, hydrogen gas is set 
free, and small crystals of zinc-oxide are deposited upon the metal : if 
the zinc is strongly ignited, the oxide sublimes on the tube in small 
shining crystals. (Kegnault, Ann* Ckim. Phy$, 62, 350.) If the zinc is 



6 ZING. 

feebly ignited, the oxide is obtained partly in amorphous globules, partly 
in transparent rhombic laminsd. (Haldat, Ann. Chim, Fhys. 46, 72.) All 
acids which retain their oxygen somewhat strongly — even weak acids— 
erolve hydrogen gaa with water and zinc. The purer the zinc, the more 
slowly does it dissolve in dilute acids, unless it is in contact with platinum 
or some other electro-negative metal (I. 347). In aqueous alkalis, solu- 
tion takes place more slowly than in acids. — 4. Red-hot zinc converts 
carbonic acid gas into carbonic oxide, and forms with phosphoric acid a 
mixture of phosphide of zinc and phosphate of zinc-oxide. In the moist 
way, it decomposes sulphurous acid, strong sulphuric acid (on the appli- 
cation of heat), selenic, chloric, nitric, molybdic, and arsenic acid. From 
the oxides of arsenic, antimony, tellurium, bismuth, cadmium, tin, lead, 
iron, cobalt, nickel, copper, mercury, silver, gold, platinum, palladium, 
rhodium, iridium, and osmium, dissolved in acids, it withdraws all the 
oxygen and precipitates the metals, being itself dissolved in the form of 
oxide; and from the higher oxides of titanium, tungsten, molybdenum, 
chromium, vanadium, uranium, manganese, and iron, dissolved or diffused 
in acids, it withdraws a part of the oxygen. 

Preparation. Zinc is heated nearly to combustion in a capacious 
crucible, placed in the furnace in a slanting position — the surface of the 
metal frequently renewed — and the oxide, which is deposited in woolly 
masses, removed from time to time from the crucible, and then rubbed up in 
water and levigated, to free it from adhering grains of metallic zinc. 
This process yields the true Flores zinci, which, if they are prepared from 
ordinary zinc, likewise contain the oxides of the metals with which the 
zinc itself is contaminated. Hence Wittstein recommends zinc purified 
by distillation. — 2. Sulphate of zinc (or any other soluble zinc-salt) is 
first prepared in a state of purity, then mixed with an alkaline carbonate 
to precipitate the carbonate of zinc, and the latter thoroughly washed, 
and afterwards dried and ignited. This process gives the zinc-oxide 
prepared in the wet way : Zincum oxydaXum via humida paralum.-^ 
a, Preparation of the pure Zinc-sulpkate, The white vitriol of commerce 
cannot be used for this purpose, because it usually contains sulphate of 
magnesia : the best salt for the purpose is that obtained by dissolving 
zinc in dilute sulphuric acid. Since common oil of vitriol often contains 
lime, and fuming oil of vitriol contains alumina, it is best to use the 
rectified acid. The solution may contain — arsenic, cadmium, tin, lead 
(a trace at most of this last metal, since sulphate of lead is nearly inso- 
luble), copper, manganese, iron, nickel, and cobalt. The quantity of 
iron dissolved is least, according to Wackenroder, when the dilute acid 
is made to act on the metal in the cold. By mixing the solution of zinc- 
sulphate with ench a Quantity of free sulphuric acid that a portion of the 
liquid treated ^ith sulphuretted hydrogen water no longer gives a white 
precipitate (sulphide of zinc), then saturating it with sulphuretted 
hydrogen gas and leaving it in a closed vessel for several days, the 
arsenic, cadmium, tin, lead, and copper are completely precipitated in the 
form of sulphides. The liquid is then decanted and filtered without 
washing — ^lest any portion of the precipitated metals should re-dissolve-^ 
and the excess of sulphuretted hydrogen expelled by bailing. If the 
dilute sulphuric acid has been allowed to act for several weeks in an open 
yessel, and without heating, on granulated zinc in excess, till no more gas 
is evolved, even on Agitation, the metals just mentioned as precipi table by 
sulphuretted hydrogen are thrown down in the metallic state by the 



ZINC-OXIDE. 7 

excess of rinc; so that the solution, when acidulated with sulphoric acid, 
gives no precipitate with sulphuretted hydrogen, and consequently the 
treatment with that liquid may be dispensed with. The cadmium, tin, 
lead, and copper may likewise oe precipitated in the metallic state by 
leaving the solution of the sine-sulphate for some time, either warm or 
cold, in contact with metallic zinc, or by boiling it with that metal (Dalk, 
Berl. Jahrb, 24, 2, 74; Horst, Br, Arch. 7, 75; Wackenroder) : in all 
cases, however, a portion of the solution thus purified should be mixed 
with excess of sulphuric acid, then saturated with sulphuretted hydrogen, 
and left to itself for a few days. If a precipitate is thereby produced, 
the whole of the solution must be treated with sulphuretted hydrogen. 

It still remains to separate any iron, cobalt, nickel, or manganese that 
may be present. If the object in view is the preparation of pure zinc- 
sulphate, the solution is first freed from a portion of the metals just 
mentioned, and likewise from the excess of acid, by evaporating and 
cooling, and then decanting the mother-liquid from the crystals. The 
crystals are then re-dissolved in water; -^ of the solution mixed with 
carbonate of soda to precipitate carbonate of zinc; the precipitate, after 
thorough washing, diffused through the rest of the solution; and chlorine 
gas passed through the liquid, which must be constantly agitated, till a 
large portion of the zinc-carbonate is dissolved, and the rest has acquired 
a brownish colour from admixture of sesquioxide of iron and the peroxides 
of manganese, cobalt, and nickel. The liquid is then set aside for some 
time in a warm place and frequently agitated — afterwards mixed with 
sulphuric acid, because a basic salt has been formed in the preceding 
process; then evaporated to the crystallizing point, and the crystals freed 
by re-crystallization from adhering chloride of zinc. The same end may 
be attained by the following methods: — Veltmann (BerL Jahrb, 29, 1, 
59) mixes the solution of zinc-sulphate with chlorine-water (which, how- 
ever, requires the use of large vessels), and adds zinc-oxide to it. 
Schindler {Mag. Pkarm. 26, 74) saturates the dilute solution with 
chlorine (a concentrated solution does not absorb enough) and then 
digests it with zinc-oxide. Bonnet (Ann, Pharm. 9, 165) precipitates 
carbonate of zinc from a portion of the solution, washes it, diffuses it in 
water, passes chlorine gas through the liquid, and mixes the resulting 
oxychloride of zinc with the rest of the solution. If, on the other hand, 
the preparation of pure zinc-oxide from the solution be the only object in 
view, the liquid is mixed with a quantity of carbonate of soda sufficient 
to produce a copious precipitate; chlorine gas passed through it, with 
agitation, till the greater part of the precipitate is dissolved; and the 
solution filtered. (Greve, Br. Arch. 22, 40; Wackenroder.) Or, the 
solution of zinc-sulphate is mixed with chloride of soda, then left to itself 
for 24 hours, and carbonate of soda cautiously added till a perfectly white 
precipitate begins to form. (Jansen, Mag. Pharm. 26, 74; Herberger, 
Repert. 48, 382; Frederking, Repert. 56, 72.) The chloride of soda must 
be prepared with carbonate of soda and chlorine gas, not with carbonate 
of soda and chloride of lime, because in that case it might contain lime. 
Hermann {Schw. 46, 249) mixes the solution with chloride of lime con- 
taining excess of lime; evaporates the liquid to the crystallizing point; 
separates the crystals from the mother-liquid, which may still contain 
cobalt and nickel; dissolves them in the smallest possible quantity of cold 
water, and filters to separate gypsum. Zinc- oxide thus prepared may 
contain lime and magnesia, because the gypeum may not be completely 



8 ZINC. 

separated, and the lime used in preparing chloride of lime often contains 
magnesia. (Greve, Veltroann, Wackenroder.) 

There are likewise a few methods of purification, chiefly directed 
towards the separation of iron. The solution mixed with carbonate of 
zinc is exposed to the air for several months till the iron is completely 
precipitated. (Martins, Eepert, 41, 208; Clamor-Marquart, Ann, Pharm. 
7, 20.) The solution is boiled with zinc-oxide. (Geiger.) Since the pre- 
cipitation of the iron depends upon its conversion from protoxide into 
sesquioxide by the oxygen of the air, it would be necessary, in applying 
this method, to heat the solution for a long time, and in that case basic 
sulphate of zinc would be formed. (Wackenroder.) A solution of 16 
parts of zinc-sulphate is boiled with 1 part of nitric acid, till it is reduced 
to a thickish mass; then re-dissolved in water, boiled with 1 or 1^ pt. pure 
zinc-oxide, and filtered. (Trommsdorff, Taschenb. 1823, I.) It is not 
easy to oxidize the iron completely; the filtrate contains basic zinc- 
sulphate which must be re-converted into monosulphate by the addition of 
a small quantity of sulphuric acid. (Schindler.) 9 parts of crystallized 
zinc- sulphate are heated in a crucible with 1 part of nitre, gently at first 
— then, after the water of crystallization has been driven ofi*, to strong 
redness — and kept at that heat till a portion dissolved in water yields a 
filtrate free from iron : the whole is then dissolved in water and filtered. 
(Bucholz, Fharm. Boruu,) Artus (t/. pr. Chem, 26, 508) mixes 50 parts 
of finely powdered zinc-sulphate very intimately with 1 part of nitre; 
heats the mixture in a crucible, stirring it all the while with a porcelain 
spatula, till it is dry; then raises the heat somewhat higher; afterwards 
dissolves in hot water; filters to separate oxide of iron, and boils the 
filtrate for a short time with purified charcoal to separate any manganese 
that may be present. Geiger recommends igniting the zinc- vitriol with 
y^ nitrate of zinc-oxide or baryta; if the latter salt be used, strong ignition 
IS necessary. Dalk mixes the solution of zinc-sulphate with infusion of 
galls, and exposes it to the air in a basin as lonff as a violet film continues 
to form upon it; then evaporates to dryness, aissolves, and filters. To 
remove the excess of tannin, Wittstein {Repei't, ^5y 218) digests the 
filtrate for 24 hours with recently ignited charcoal; and Walcker {Ann. 
Fharm, 4, 84) precipitates it by boning with white of ^gg, A solution 
of 4 parts zinc- sulphate in 20 water set aside for 5 days in contact with 
recently ignited wood-charcoal deposits all the iron it contains upon the 
charcoal. (Stickel, Wittstein.) 

It has likewise been proposed to dissolve zinc in hydrochloric, nitric, 
or acetic acid, and then purify the solution in a similar manner. 

^ Defierre («7. Pkarm, 5, 70) dissolves 125 parts of zinc in 500 parts 
of hydrochloric acid — then adds 8 parts of nitric acid, and warms the liquid 
to oxidize the iron; evaporates to dryness; dissolves the residue in water; 
leaves the solution for 24 hours in contact with 8 parts of carbonate of 
lime, and filters. The clear liquid is precipitated while hot, by gradually 
adding dilute ammonia as long as any precipitate continues to form, the 
solution retains but very little zinc-oxide, and the precipitate, after 
thorough washing, contains scarcely a trace of any other salt. ^ 

h. FrecipUcUion of the purified Zinc-sohUion. — The solution is boiled 
in a porcelain basin, and carbonate of soda added in small portions till 
slightly in excess; the boiling is then continued for a time, in order that 
the precipitate may aggregate more closely. Or, a dilute solution of 
I At. zinc-sulphate is precipitated, in the cold and with agitation, by a 
solution of somewhat less than 1 At. carbonate of soda, the filtering being 



ZINC-OXIDB. 9 

deferred for some time in order that the gelatinous precipitate may 
become pulverulent. Another method is to boil a solution of 9 parts of 
crystallized carbonate of soda in a clean copper vessel, and cause a solu- 
tion of 2 jparts of zinc to flow into it in a thin stream — ^the soda- 
solution being constantly stirred— so that the liquid may not boil over 
from escape of carbonic acid, nor the undecomposed zinc-solution come in 
contact with the copper vessel. The precipitate is easy to wash, and is 
free from soda, provided the boiling has been kept up during the whole 
time of mixing. (Schindler.) If any portions of soda and sulphuric acid 
are carried down with the precipitate, the greater part may be removed 
by boiling for a while after precipitation, but not all. (Wackenroder.) 
If the zinc-solution be precipitated by carbonate of soda in the cold, an 
excess of the latter must be avoided, as otherwise the precipitate will 
retain its gelatinous character even after long standing, and will contain 
considerable quantities of soda and sulphuric acid. For 1 part of zinc- 
vitriol dissolved in 20 parts of water, 1 part of crystallized carbonate of 
soda dissolved in 10 parts of water is sufficient. The two solutions are 
mixed at once, and rapidly stirred ; the transparent jelly thereby pro- 
duced is converted in the course of 24 or 36 hours, with evolution of gas, 
into a loose powder which is easy to wash. Acid carbonate of zinc 
remains in solution, together with any lime and magnesia that may 
perchance be present. The oxide obtained by ignition from the carbonate 
precipitated in the cold exhibits a fainter tinge of yellow than that 
prepared from carbonate precipitated from hot solutions. (Schindler, 
Wackenroder.) The zinc-solution may likewise be mixed in the cold 
with carbonate of ammonia, till the liquid is perfectly neutral. The 
precipitate, like that produced by cold carbonate of soda, contains but a 
trace of sulphuric acid. The precipitate obtained with carbonate of 
ammonia in a hot solution, contains a considerable quantity of sulphuric 
acid. (Wackenroder.) Precipitation by caustic ammonia^ potash, or soda, 
does not give good results; if too small a quantity of the alkali be used, 
a basic salt is precipitated; with a larger quantity, the precipitate is 
liable to be contaminated with an alkaline salt, and a still larger 
((uantity completely re-dissolves it. The precipitated zinc-carbonate 
is washed partly by subsidence and decantation, partly by pressure, and 
lastly on the Alter. The dried precipitate is gently ignited in a covered 
earthen crucible. — The most direct mode of obtaining pure zinc-oxide 
would be to precipitate pure nitrate of zinc by carbonate of ammonia, and 
ignite the precipitate. 

Testing of the Zinc-oxide,— 'ThQ oxide prepared by (1) should be 
white ; that obtained by (2) white, with a faint tinge of lemon-yellow. 
A brownish white tint indicates the presence of foreign metallic oxides; 
pure whiteness and considerable density in the oxide (2) shows the 
presence of sulphuric acid, chlorine, and soda. — 1. Metallic zinc: Evo- 
lution of hydrogen on solution in acids. — 2. SulphuHc acid or chlorine: 
The solution of the oxide in nitric acid gives a precipitate with chloride 
of barium or nitrate of silver. — 3. Soda: M&y be extracted by water, 
partly in combination with sulphuric or hydrochloric acid. — 4. Lime and 
Magnesia: The solution of the oxide in hydrochloric acid, when preci- 
pitated by hydrosulphate of ammonia and filtered, yields chloride of 
calcium or ma^esia, on evaporation and ignition. — 5. Silica: From 
crude potash, when that substance is used for the precipitation, or from 
the crucible. Left behind on dissolving the oxide in hydrochloric acid.-— 



10 ZINC. 

6. Seaquioxide of Manganese: Partly left behind when the zinc-oxide n 
dissolved in dilate nitrio acid. Produces a green colour when ignited 
with carbonate of soda and nitre. — 7. Sesquioxide of Iron: The solation 
in hydrochloric acid giyes a red colour with snlphocyanide of potassium^ 
and exhibits the other reactions of ferric salts. — 8. Oxide of Lead: Boiling 
carbonate of soda extracts this oxide almost completely; the filtrate 
blackens on the addition of hydrosulphuric aoid, and then, on the addition 
of an acid, gives a precipitate of sulphide of lead. The oxides of copper 
and cadmium remain undissolved in this process. — The solution of tho 
zinc-oxide in hydrochloric or nitric acid gives a precipitate of lead- 
sulphate on the addition of a large quantity of sulphuric acid. — 9. Oxides 
of Cadmium and Copper: The liquid filtered from the lead-sulphate, or 
the hydrochloric acid solution of the zinc-oxide freed from lead by boiling 
with carbonate of soda, gives with hydrosulphuric acid, a yellow or brown 
precipitate, which must be further examined. — 10. Oxides of Nickel and 
Cobalt. — See the methods of Berzelius and Ullgren. {Jahretib,, 21, 22, 
143 and 145.) 

Sublimed and mostly impure zinc-oxide is occasionally obtained, in 
the form called Fumace'Calamine, Cadmia foma^cum, T€Uia, or, when it 
is whiter, Pompholyx, in the preparation of brass and in the smelting of 
zinkiferoQS ores in the smelting-fumace, in the shaft of which it collects. 
A furnace-calamine from an iron-smelting furnace examined by Anthon 

iJ, pr, Chem. 9, 4), was found to contain zinc-oxide 74*9, lime i'7> 
erric oxide 13*9, lead- and cadmium-oxide 0'8, silica, with a small 
portion of cobalt-oxide 2 '5, quartz adventitiously mixed 4*3 (loss 1*9). 

Properties, Crystalline system, the hexagonal. Red zinc-ore occnrs 
in six-sided prisms, of specific gravity 6*2. (Vernon.) In furnace- 
calamine, Koch found crystals having the forms of Figs, 131 (some more 
obtuse, others more acute), 132, 135, 137, and 138. — At the zinc-smelting 
works at Filisur in the urisons, there are found sublimed in the upper 
parts of the crucibles in which the zinc is melted, amber-coloured, trans- 
parent, hard, shining, six-sided prisms {Figs. 135 and 138), which have a 
density of 6*0, yield a white powder becoming yellow when heated, and 
consist of zinc-oxide with a trace of sulphide. (Vernon, PhU, Mag, 
Ann. 7,401). — In the cracks of the earthen tubes in which zinc is dis- 
tilled, Laurent and Holms (Ann, Chim. Phys. 60, 333) found microscopic 
six-sided prisms. When 1 part of zinc-oxide is heated to commencing 
redness with from 4 to 6 parts of potash-hydrate, and the product 
exhausted with water, dingy yellow needles of zinc-oxide are left behind. 
(Becqnerel, Ann. Chim. Phys. 51, 105.) — Specific gravity of zinc-oxide 
=5-600 (O. Boullay), 5-7344 (Karsten).— IT According to Brooks {Pogg, 
74, 439) the specific gravity of pure crystallized zinc-oxide is between 
5'61 and !i'Q^. — Crystalline zinc-oxide, deposited in an earthen retort 
used for the distillation of zinc, was found by W. and T. Herapath to be 
aggregated in acuminated masses of small, shining, transparent crystals, 
which appeared to be right rhombic prisms; their specific gravity was 
5-53. When treated with acids, they yielded, without effervescence, 
from 88*5 to 92 per cent, of zinc-oxide, and an insoluble crystalline 
residue consisting of ZnO, SnO*. (^Chem. Soc. Qu, J., I. 42.) % 

The oxide prepared by (1) has the form of white flakes, or, after 
levigution, that of a white powder The oxide prepared by (2) is a 
white, loosely -coherent powder^ having a slight tinge of lemon-yellow. 



ZINO-OIUDE. 11 

Both varieties acquire a lemon-yellow colour when heated, but lose it 
a^in on cooling. The change of colour is not accompanied either by 
absorption or by evolution of oxygen. The yellowish tint which the 
second variety, whether it has been gently or strongly ignited, exhibits 
in the cold, is sometimes attributed to the presence of foreign oxides. It 
is, however, exhibited even by the perfectly pure oxide; and, if the oxide 
formed by the combustion of zinc be dissolved in acids, precipitated and 
ignited (Jansen), or dissolved in nitric acid, evaporated and ignited 
(Schindler), it likewise acquires this yellow tinge; in fact, the oxide pre- 
pared by precipitation and ignition, and which is probably less dense 
than the other variety, appears to possess this colour as an essential 
character. — The carbonate precipitated from cold solutions, yields on 
ignition, a lighter oxide than that which is precipitated hot; and this 
lighter oxide acquires a brighter yellow colour by ignition; if on the 
contrary, the oxide is denser from the presence of sulphuric acid, chlo- 
rine, and soda, it does not exhibit this tinge of yellow when cold. 
(Wackenroder.) — The oxide (2) loses its yellowish tint by strong ignition 
on platinum. (Schindler.) — Zinc-oxide emits a strong light in the blow-' 
pipe flame. It is volatile at a strong white heat. 









Berzeliua. 
Proust. earlier, later. 


Gay- 

Lussac. 


Jaoque- 
lain. 


Zn 

O 


32-2 .... 
80 .... 


80-1 
19-9 


.... 80 .... 80-39 .... 80-1 
.... 20 .... 19-61 .... 19-9 


.... oO'oo .... 
.... 19-62 ... 


80-534 
19-466 


ZnO .... 


40-2 .... 


1000 


.... 100 .... 100-00 .... 1000 
Thomson* Dobereiner. 


.... 10000 .... 

Clem. & 
Desormes. 


100-000 




ZnO .. 

O 




80-54 .... 81-64 

19-46 .... 18-36 


82-15 
17-85 






ZnO 




10000 .... 10000 


10000 





DecomposUums, By potassinm, at a gentle heat, and without com- 
bustion. By charcoal at a strong red heat, yielding zinc vapour and 
carbonic oxide gas. If the zinc-oxide is in excess, carbonic acid gas is 
likewise formed. (Gm.) By carbonic oxide gas, with difficulty, yielding 
zinc and carbonic acid gas. (Dulong, Despretz, Ann, Chim, Pkys, 43, 222; 
also Pogg, 18, 159; Gm.) By hydrogen gas, with great difficulty, yield- 
ing metallic zinc and water. (Despretz, Wackenroder, Gm.) By sulphur, 
the products being sulphide of zinc and sulphurous acid. 

OombiTiations.^a* With water. — Hydrate op Zino-oxide, or Zinc- 
hydrate. — Ignited zinc-oxide immersed in water does not enter into 
combination with it. (Wackenroder.) — Preparation, 1. When zinc in 
contact with iron is immersed in aqueous ammonia for eight days, and the 
evolved hydrogen allowed to escape through a gas-delivery tube, there 
are deposited on the zinc and on the sides of the glass, small, transparent, 
colourless, rhombic prisms, which have a glassy lustre, are permanent in 
the air, and leave zinc-oxide when ignited. (Schindler.) Nickles has like- 
wise found that hyd rated zinc-oxide crystallizes in right rhombic prisms. 
(jV. Ann. Ckim. Phys. 22, 31 .) — 2. Nitrate of zinc- oxide is precipitated 
by an insufficient quantity of potash, and the light, flocculent precipitate, 
washed till the water no longer dissolves out any zinc-salt. (Bonnet.) If 
an excess of potash is used, the precipitate contains potash. Sulphate 
and hydrochlorate of zinc-oxide yield an impure hydrate. (Bonnet*) 



12 ZINC. 

Cry$taUized. Schindlcr (1. 

ZnO 40-2 .... 81-71 81-62 

HO 9-0 .... 18-29 18-38 



ZnO, HO 49-2 .... 10000 10000 

h. With Acids, forming tho Salts op Zinc-oxide or Zinc-salts. 
The affinity of zinc-oxide for acids is considerable. The salts are colour- 
less, unless the acid itself is coloured. Thej are mostly soluble in water; 
the solutions redden litmus, and have a disagreeable, rough, and somewhat 
ferruginous taste. They exert an emetic action. When ignited, they 
give up all their acid, provided it is volatile; the sulphate, however, gives 
up its acid with difficulty. They produce a white deposit on charcoal in the 
inner blowpipe flame; when moistened with nitrate of cobalt and ignited, 
they yield a green residue. — Free hydrosulphuric acid, added to a solution 
of zinc-oxide in the weaker acids, such as acetic acid, precipitates the whole 
of the zinc in the form of white hydrated sulphide; from solutions of 
zinc-oxide in the stronger acids, such as sulphuric, nitric, and hydro- 
chloric acid, sulphuretted hydrogen precipitates nothing, if the acid is in 
great excess, and only a portion of the zinc, if the acid is not in excess. 
Hydrosulphate of ammonia precipitates zinc-salts completely; the pre- 
cipitated zinc-sulphide is insoluble in hydrosulphate of ammonia, and 
likewise in caustic ammonia, potash, and soda, and their carbonates, and 
only slightly soluble in acetic acid. With 1 part of zinc in the form of 
sulphate dissolved in 10,000 parts of water, hydrosulphate of potash still 
gives flakes; in 20,000 parts of water, only a faint opalescence. (Las- 
saigne.) — Caustic alkalis throw down a white gelatinous hydrate of zinc- 
oxide, soluble in excess of ammonia, potash, and soda. The alkaline 
solution thus formed gives a white precipitate with hydrosulphuric acid; 
but the precipitation is not complete till after some time. — Zinc-salts 
dissolved in water give, with carbonate of ammonia, a white gelatinous 
precipitate of carbonate of zino-oxide, soluble in excess of the re-agent; 
with carbonate of potash or soda, they form a similar precipitate, which, 
however, is insoluble in excess of the re-agent, but is dissolved on passing 
chlorine through the liquid. If the zinc-solutiou is mixed with sal- 
ammoniac, carbonate of potash or soda gives a precipitate only after long 
boiling. (H. Rose.) A solution of zinc-vitriol, containing only 1 part 
of zinc in 10,000 parts of water, still gives slight flakes with carbonate 
of potash or soda; with 20,000 parts of water, the precipitate appears 
after some time only. ^Lassaigne.) Bicarbonate of potash or soda pre- 
cipitates zinc-salts with copious evolution of carbonic acid. — Zinc-salts 
are not precipitated by carbonate of lime (Fuchs, Sckw, 02, 191); the 
carbonates of baryta, strontia, lime, and magnesia, do not precipitate 
them at ordinary temperatures, but completely at a boiling heat. 
(Demar9ay, Ann. Pharm, 11, 240.) — Phosphate of soda gives a white 
precipitate, soluble in ammonia and in potash. — Oxalic acid precipitates 
zinc-oxide in the form of a white oxalate, and, according to Thomson, the 
precipitation is complete. If the solution is very dilute, the turbidity 
does not appear till after some time. (H. Rose.) . The precipitate is pro- 
duced, even when tho zinc-salt contains a large excess of acid, provided 
it be considerably diluted. The precipitated oxalate is soluble in 
ammonia and in potash. — Zinc-salts give, with ferrocyanide of potassium, 
a white gelatinous precipitate, and with the ferricyanide, a yellowish red 
precipitate, both soluble in hydrochloric acid: I part of zinc in the form 
of sulphate, dissolved in 10,000 parts of water, gives a slight turbidity 



ZINC-CARBONATES. 13 

with ferrocyanide of potassiam; in 20,000 parts of water, a very slight 
turbidity; with the same quantity of salt in 80,000 parts of water, the 
turbidity does not appear till after 5 or 10 minutes. (Lassaigne.) 
Tincture of galls precipitates the basic salts of zinc, or those which 
contain a weak acid, even when the solutions are very dilute. (Schindler.) 
Zinc-salts are not precipitated by heavy metals,, or by sulphite of 
ammonia. — Those zinc-salts which are insoluble in water, dissolve in 
hydrochloric acid and in a hot aqueous solution of sal-ammoniac. 
c. With alkalis and with certain oxides of the heavy metals. 



C. Peroxide of Zikc? 

Th^nard (Ann. Cliim, Phys. 9, 55) obtained this compound by treating 
hydrated zino-oxide with aqneous peroxide of hydrogen at 0°. It forms 
a gelatinous mass, which, even at ordinary temperatures, and still more 
at 100° gives off oxygen gas, and dissolves m acids, forming a salt of zinc- 
oxide mixed with peroxide of hydrogen. Possibly, a compound of zinc- 
oxide with peroxide of hydrogen. 



Zinc and Hydrogen. 

A. Hydride of Zinc%—{7id. Ruhland, Sckw. 15, 418.) 

B. ZincureUed Hydrogen Gas 9 — Vauquelin obtained this gas by 
ignitine 4 parts of roasted blende with 1 part of charcoal powder — 
Colourless, lighter than air, heavier than hydrogen. Has a faint but 
unpleasant odour. When set on fire by a flaming body, it burns in the 
air with a bluish and yellowish white flame, forming white clouds of 
zinc-oxide, and depositmg a small quantity of metallic zinc. When 
mixed with chlorine, it explodes by contact with flame, producing hydro- 
chloric acid and chloride of zinc. - Not decomposed by nitric acid or by 
easily reducible metallic salts. Not absorbed by water. Does not combine 
with salifiable bases. 

Zinc and Carbon. 

A. Carbide of Zinc 9 — Nearly all the zinc of commerce contains carbon. 
—The black powder which is left behind in the distillation of cyanide of 
zinc, and which, when thrown on red-hot coals, bums and forms oxide of 
zinc, is regarded by Berzelius as carbide of zinc. 

B. Carbonate op Zinc-oxide or Zinc-Carbonate, — Carbonate of 
Zinc.* — Ignited zinc-oxide does not absorb carbonic acid from the air 
(Schindler); but if carbonic acid gas be passed through ignited zinc-oxide 

* The longer terms, carbonate of zinc-oxide, nitrate of sUTer-oxide, &c.« are those 
which accord most strictly with the received nomenclature of the alkaline salts, such as 
carbonate of soda, nitrate of lime, &c.; the shorter terms, zinc-carbonate, silver-nitrate, 
5cc., are convenient abbreviations of them. The more ordinary terms, carbonate of 
zinc, nitrate of silver, &c., though not strictly correct in point of form, are nevertheless 
convenient in the case of metals which, like zinc, lead, and silver, have but one oxide 
which forms salts. [W.] 



14 ZINC. 

dijffdaed through water in rach quantity as to fonn a semifluid mixtore, 
the oxide takes up 4*585 per cent, of carbonic acid and 8347 water. 
(Wackenroder.) 

a. Octcbasic, — Obtained by boiling octobasic sulphate of zinc-oxide 
with aqueous carbonate of soda. — 6. Quadrobaaic. — By boiling the 
quadrobasic sulphate with carbonate of soda. (Schindler.) 

a. Sdiindkr. 

SZnO 88-94 88*92 

CO* 6-08 6-11 

2HO 4-98 4-97 



• 


8ZnO,C03 + 2Aq 


10000 




10000 




b. 








Schindler. 


4ZqO 





160-8 


•t«. 


8008 


80-00 


co» .. 




220 


..•• 


10-96 


11-01 


2H0.. 


•■••■■■••»••■■•••«••» 


180 


•••• 


8-96 


8-99 



4ZnO,C03 + 2Aq 2008 .... 10000 10000 

e. With 2 At. acid to 5 At base, — This is probably the compoaitioa 
of Zinc-bloom. — 1. Produced when zinc covered with water is exposed to 
the air. (Bonsdorff.) — 2. When a zinc-salt is precipitated by monocar- 
bonate of ammonia, potash or soda. In this reaction, carbonic acid is 
set free; and if the solutions are cold, a quantity of zinc-oxide is dissolyed 
by it in the form of acid carbonate, greater in proportion to the quanti^ 
of water present; on boiling, however, the carbonic acid is evolved. It 
16 difficult to obtain the precipitate quite free from alkali and from the 
acid of the zinc-salt used. — a. A boiling solution of zinc-sulphate is added 
to boiling <»,rbonate of soda (or potash), which may be in excess; yiolent 
effervescence ensues, and a very soft, loose powder is formed, which 
resembles magnesia alba when dry, and is free from alkaline carbonate, 
if the boiling be continued for some time after mixture. (Schindler.) — 
5. The solution of I At. zinc-sulphate and 1 At. carbonate of soda (or 
potash) are mixed cold; in this case, the translucent jelly which separates 
at first is soon transformed, with evolution of carbonic acid, into an opaque 
powder. If the carbonate of soda is in excess, a portion of it is taken up 
by the precipitate and cannot be removed by subsequent boiling; the 
jelly is then stiffer, but does not become pulverulent even after standing 
for weeks; when washed and dried, it forms a coherent mass which adheres 
tenaciously to the tongue. (Schindler.) — c. The solution of zinc-sulphate is 
mixed with sal-ammoniac, and carbonate of soda added, in. the cold, till a 
glass rod moistened with hydrochloric acid, gives white fumes when held 
over the liquid. The precipitate, after being washed and dried at 1 00° in 
vacuo, is free from soda and sulphuric acid. (Berzelius, Jahre^. 15, 130.) 
d. Solution of zinc-sulphate is precipitated in the cold with a precisely 
equivalent quantity of carbonate of ammonia. The precipitate, which is 
crystalline at first, becomes very light after drying. (Wackenroder.) — 
Solution of zinc-nitrate is precipitated cold by an exactly equivalent 
quantity of carbonate of soda. (Wackenroder.) — The precipitate obtained 
by decomposing zinc-salts with alkaline carbonates at ordinary tempera- 
tures, is, when recently precipitated, much lighter than that obtained 
from hot solutions. The former contains originally dicarbonate of zinc- 
oxide together with a large quantity of water, but loses so much water 
and carbonic acid in drying, that it becomes identical in composition 
with the salt precipitated from hot solutions. (Wackenroder.) 



ZINC-CARBONATE. 



15 



White, looBelj-cofaerent powder, resembling magnesia alba. Dissolyes 
in 20C0 — 8000 parts of water (in 44642 pts. Fresenius)^ but separatee 
from the solution when heated, and does not re-dissolve on cooling. 
(Schindler.) According to Wbhler {Fogg. 2S, 616), this salt is deposited 
in small shining crystals when an aqueous solution of the compound of 
zinc-oxide and potash is exposed to tne air. — Dissolves readily in a cold 
aqueous solution of hydrochlorate or nitrate of ammonia (Brett, Wittstein), 
and disengages ammonia when heated therewith. (L. Thompson.) 











Wacken- 


1 




Wacken- 






BoDsdorff. Schindler. roder. 




Schindler 


roder. 






(1.) 


(2, a.) 


(2. a.) 




(2,4.) 


(2, h,) 


5ZnO.... 201 


.... 73-90 


.... 71-25 


.... 73-5 


.... 72-68 


»... 


72-22 


.... 72-87 


2C0».... 44 


.... 16-17 


.... 14-19 


.... 14-6 


.... 12-74 


.... 


15-30 


.... 12-70 


3H0.... 27 


.... 9-93 


.... 14-56 


.... 11-9 


.... 14-02 


•«.. 


12-48 


••,« lo'9v 


NaO .... 


• •■• 


• •*• 


• ■«• 


.... 0-28 








S0» .... 


••■• 


••■• 


• •»• 


.... 0-28 


.... 


, 


0-50 


272 


.... 100-00 


.... 100-00 


.... 100-0 


.... 10000 


>••. 


100-00 


.... 10000 




Berzelins. 


Wackenroder. 




Smithson. 






(2. c.) 


(2. A) 


(2. 


«.) 


Zinc-bloom, 


ZnO 




73-35 


73-23 


73-34 


• ••• 


71-4 


CO« 




15-94 


12-80 


12- 


70 


• #•■ 


13-5 


HO 




10-71 


13-79 


13-96 


• •■fl 


15-1 


NaO 








trace 






SO» 






018 











100-00 



100-00 



10000 



100-0 



Berzelius and Wackenroder examined the salt dried at 100°; with respect 
to the other analyses no such particulars are stated. According to 
Berzelius, the salt is composed of 5ZnO, 2CO' + 3 Aq. = 2(ZnO, CO') 
4- 3(ZnO, HO). Schindler prefers the formula : 8ZnO, 3C0*+ 6 Aq. and 
Wackenroder gives the preference to ]2ZnO, 4C0'-f 9 Aq. The analyses 
of Smithson and Bonsdorff give nearly: 3ZnO, CO* + 3 Aq. — T Lefort 
{J. Fharm, 3rd series, 11, 329) gives for the salt obtained by precipitat- 
ing a zinc-salt with carbonate of soda or potash at a boiling heat, the 
formula: 8ZnO, 3CO« + 6HO. IT 

d. Bibanc-^Dicarhonate. — Formed by precipitating a solution of 
zinc-sulphate at ordinary temperatures with sesqui carbon ate of soda, 
washing the precipitate thoroughly, and drying it in the air. — Soft, white 
powder. (Boussingault, jinn. Chim. Fhys. 29, 284.) By precipitating 
from hot solutions, the salt c is obtained. (Schindler.) 



4ZnO 160-8 

2C0» 44-0 

3HO 27-0 



69-37 
18-98 
11-65 



Boussingault. 
70 
19 
11 



2(2ZdO,CO») + 3Aq.... 2318 



2ZnO 80-4 

C0« 22-0 

2H0 18-0 



10000 



66-78 
18-27 
14-95 



100 

Schindler. 
67-43 
18-00 
14-57 



2ZnO,CO*+ 2Aq. 1204 



10000 



10000 



e, Manocarbonate. — Found in nature as Zinc-9par and Calamine. 
Crystalline system the rhombohedral : Fig, 141, 143, 145, and other 
forms; r» : r*=107M0'; r' : r 6tfAtW=72'» 20'. (WoUaston.) Cleavage 



16 2INC. 

parallel to r. Specific gravity^ 4'd765 (Kanten), 7*442 (MohsV Hard- 
ness equal to that of apatite. White^ transparent. Not faeiole before 
the blowpipe. Tnms green when ignited with nitrate of cobalt. Dis- 
solves in acids with effervescence; soluble in caustic potash. According 
to Schindler^ this salt may be obtained artificially, containing, however, 
a small quantity of water (probably from admixture of salt^Q: 1. By 
precipitating in the cold a solution of 1 At. zinc-sulphate in ten times its 
weight of water with a solution of 1 At. bicarbonate of potash or soda. 
The loose, non-gelatinous precipitate is, after drying, soft, white, and 
much heavier than the salt c, (Berzelius obtained by this process the 
salt c, containing 73 per cent, of zinc-oxide; Lefort obtained by the same 
process, a salt containing : 3ZnO,CO'-)-6HO), — 2. The aqueous solution 
of the acid salt /, when left to evaporate spontaneously, deposits the 
monocarbonate in the form of a granular powder. (Schindler.) 









Smithson. Schindler. 


ZnO 

CO« 

HO 


40-2 
220 


.... 64-63 
.... 35-37 
.... 


fiomenetihire. Derijyahire. (1.) (2.) 
.... 64-8 .... 65-2 .... 63-05 .... 63-0 
.... 35-2 .... 34-8 .... 33-53 .... 34-9 


ZnO,CO« 


62-2 


.... 100-00 


.... 1000 .... 100-0 .... 100-00 .... 1000 



IT Manganiferoui Zinc-tpar, The following varieties of zinc-spar 
from Aachen containing manganese, have been analyzed by Monheim. 
(Z. ds K, Jahresb, 1848, 1225.) a, light-green, rhombohedrous: sp. gr. 
= 4'Od ; 6, dark green : sp. gr. = 3*98, both from Herrenberg ; 
Cf yellowish white from Altenberg: sp. gr. 4*20. 





a. 




h. 




e. 


ZnO, CO* 


85-78 




74-42 




84-92 


MnO, CO» 


7-62 




14-98 




6-80 


FcO.CO* 


2-24 




3-20 




1-58 


MgO,C02 


4-44 




3-88 




2-84 


Ca0,CO« 


0-98 




1-68 




1-58 


SiO» 


009 




0-20 






HO 


trace 




0-56 




1-85 


Calamine 













10115 .... 98-92 .... 99-57 

Ferruginous ZinC'tpar; Kapnitef Monheim has likewise analyzed 
several specimens of the ferruginous zinc-spar from Altenberg described 
by Breithaupt as a new unneral species under the name of Kapnite. The 
proportion of iron in those specimens being very variable, Monheim does 
not regard the mineral as a distinct species, but proposes for the light- 
green varieties, rich in zinc, the name of Ferruginous Zinc-spar, and for 
the dark-green varieties and those which turn brown by oxidation of the 
iron, the term Zinc-ironspar : (a) sp. gr. = 4*09; (6) sp. gr. = 4*15; 
(c) sp. gr.=400; {d) sp. gr.=404; (e) sp. gr.=4*00; (/) sp. gr. not 
aetermined. 

a. h, c. d. €, yi 

ZnO,CO« 71-08 .... 60*35 .... 58*52 .... 55-89 .... 40-43 .... 28*00 

FeO,CO» 23*98 .... 32*21 .... 3541 .... 3646 .... 53*24 .... 67*00 

MnO, CO* 2-58 .... 402 .... 324 .... 3*47 .... 2-18 

CaO,CO» 2-54 .... 1*90 .... 3-67 .... 2*27 .... 5-09 .... 5*00 

MgO,CO» .... 014 

Calamine .... 2*49 .... 0*48 .... 41 



100-18 ... 10111 .... 101-32 .... 98*50 .... 100*94 .... 100*00 

If. 



ZINC-PHOSPHATE. 17 

/. Acid-salt Metallic zidc^ the hydrated oxide^ and the carbonates 
a , . . e are easily soluble in excess of aqueous carbonic acid. (Comp, 
Jahn, Ann. Pharm. 28, 119.) 



Zinc and Boron. 

Borate of Zinc-oxide.— Precipitated on mixing an aqueous solution 
of zinc-sulphate with borax. White powder, insoluble in water, but 
soluble in aqueous boracic acid. Turns yellow in the fire, and is con- 
verted into a solid, compact, opaque slag. (Wenzel; comp. Tannermann, 
Kastn. Arch, 20, 14.) 

Zinc and Phosphorus. 

A. Phosphide of Zino. — a. When pieces of phosphorus are thrown 
upon melted zinc, a lead-grey mass is obtained, having the metallic 
lustre, somewhat ductile, smelling like phosphorus when hammered, and 
burning like zinc when heated. (Pelletier; comp, Landgrebe, Schw. 53, 
460). — h. The silver-white substance with conchoidal fracture which 
sublimes on igniting 6 parts of zinc with 6 phosphorus and 1 charcoal, or 
2 zinc with 1 phosphorus in a glass retort, appears to be richer in 
phosphorus than the last—c. When phosphuretted hydrogen gas is passed 
over gently heated chloride of zinc — ^whereupon hydrochloric acid gas is 
slowly evolved — and the mass afterwards digested in water, phosphide of 
zinc remains in blackish particles, which exhibit the metallic lustre, emit 
a phosphorus flame when heated on charcoal before the blowpipe, and are 
perfectly insoluble in hydrochloric acid. (H. Rose, Pogg, 24, 235.) 

B. HypopuosPHiTE OF Zinc-oxide. — The solution of zinc in heated 
aqueous hypophosphorous acid, yields by evaporation in vacuo, indistinct 
crystals, which, when heated to redness in a retort, swell up strongly, 
give off non-spoutaneously inflammable phosphuretted hydrogen, and 
leave a residue soluble in hydrochloric acid. (H. Hose, Pogg^ 11, 92.) 

C. Phosphite of Zinc-oxide. — Perchloride of phosphorus dissolved 

in water and neutralized by ammonia, precipitates a small quantity of 

this salt from a solution of zinc-sulphate, the rest remaining in solution, 

and separating when the liquid is boiled. The salt, when heated, swells 

up strongly, and gives ofi" hydrogen gas, mixed, especially towards the 

end of the reaction, with phosphuretted hydrogen. 100 parts of the 

salt dried in vacuo leave, on ignition, 79*43 parts of residue containing 

53'38 per cent, of zinc-oxide, and 46 '62 phosphoric acid. 100 parts 

of the dried salt oxidated by nitric acid and ignited, yield 81*4 parts of 

diphosphate of zinc-oxide. The salt dissolves with difficulty in water. 

(H. Rose, Pogg. 9, 29.) 

H* Roso 

2ZnO 80*4 .... 4236 .... 4314 ' 

P03 55-4 .... 29-19 .... 29-69 

6H O 54-0 .... 28-45 .... 27-17 

2ZnO,P03 + 6Aq 189-8 .... 100-00 .... 10000 

D. Ordinary Phosphate op Zinc-oxide or Zinc-phosphate. — 
a. Trip/io<pAa^.*^Pro€ipitated on mixing a solution of a zinc-salt with 

VOL. V. c 



18 



ZINC. 



dtpliospbate of ammonia, potash, or soda, the snpernatant liquid becoming 
acid. (Mitaoherlich.) When dilute eolations of sulphate of sino-oxide 
and diphosphate of soda are mixed in the cold, a translucent jelly ia at 
first produced; this, howeyer, soon becomes opaque and aggregates into a 
fine white crystalline powder. If the solutions are mixed boiling hot, 
no jelly is produced, but the pulverulent precipitate is formed at once and 
has the same composition. (Schindler.) The same compound is doubtless 
formed on digesting carbonate of zinc -oxide with aqueous phosphoric 
acid not in excess. White, crystalline, tasteless powder. Fuses easily^ 
forming a transparent and colourless glass. Insoluble in water; soluble 
in acids; likewise in ammonia and in carbonate, sulphate, hydrochloratOj 
and nitrate of ammonia — iu the last three, however, with slight turbidity. 



Anhpdrofu. 

SZnO 120-6 .... 62-«l 

cPO» 71-4 .... 3719 



Hydraied, Schindler. 

8ZnO 120-6 .... 57*43 .... 5746 

cPO» 71-4 .... 34-00 .... 33-86 

2HO 180 .... 8-57 .... 8*82 



3ZnO«cPO< 1920 



10000 



+ 2Aq 2100 



10000 



10014 



h. Diphosphate, On mixing a solution of 3 parts of sinc-sulphate 
in 32 parts of hot water, with a solution of 4 parts of crystallized diphos- 
phate of soda in 32 parts of hot water, this salt is deposited in shining 
laminas. (Graham.) In this case, the zinc-sulphate is in excess; in the 
preparation of salt a, it appears to be necessary that the phosphate of 
soda be in excess. The crystals do not lose water at 100"^; but at a 
tem|>erature below the melting-point of tin, they give off 2 At. water, 
retaining their lustre; at a red heat they fuse and give off 3 At. water. 
(Graham, Ann. Pharm, 29, 28.) 



Dried, 

2ZnO 80*4 .... 50-0 

cPO» 71*4 .... 44-4 

HO 9-0 .... 6-6 



2ZnO. 
cPO». 
3HO. 



CrystaUixed. 

80-4 .... 44-97 
71-4 .... 39-93 
270 .... 15-10 



2ZnO,HO,cPO» 160*8 



100*0 



+ 2Aq 178*8 



100-00 



c. Acid PhospTiate, By dissolving zinc, or the carbonate or phosphate 
of zinc-oxide in excess of acid and evaporating. Gummy mass which 
fuses in the fire to a transparent glass. When a small quantity of alkali 
is added to its aqueous solution, the salt a is deposited. (Wenzel.) 

E. PYRopnospnATB OF Zinc-oxide. — By precipitating a zinc>salt with 
pyrophosphate of soda. The precipitate is decomposed by boiling with 
ordinary phosphate of soda, yielding ordinary phosphate of zinc- oxide 
and pyrophosphate of soda. (Stromeyer, Sckw, 58, 129.) H The salt 
precipitated as above forms a white bulky mass, which in drying shrinks 
up like hydrate of alumina. If it be suspended in water, and sulphurous 
acid gas passed through the liquid, the whole dissolves, and the solution, 
when boiled, yields the salt in the form of a heavy, white, beautifully 
crystalline powder consisting of 2(2ZnO,5PO')-|-3Aq. Both the amor- 
phous and the crystalline s^t dissolve in acids and in caustic potash; 
ammonia likewise dissolves the salt, and alcohol added to the solution 
throws down a syrupy mass. (Schwarzenberg, Ann. Fkarm. 65, 151.) IT 

Metaphosphate op Zinc-oxide. — Formed by burning hyposulpho- 
phosphate of zinc. Transparent glass, soluble in water. (Berzelius.) 



SULPHIDB OP ZINC. 19 



Zinc and Sctlphub. 

A. Sulphide of Zinc, or Zinc-sulphide. — ^Foond in nature aaSlende, 
frequently containing sulphide of iron and sulphide of cadmium. 
Noggerath and Bischof (Schw. 65, 245) found in an old mine a quantity 
of zinc-sulpbide mixed with washings of the ore, forming a deposit some 
inches in thickness on the wood- work; it had probably oeen formed by 
the reducing action of the wood upon sulphate of zinc-oxide. Formation. 

1 . When sulphur vapour is passed over red-hot zinc, a small quantity 
of white sulphide is produced. (J. Davy.) When zinc-filings are heated 
with sulphur, the sulphur volatilizes before combination takes place. 
The sulphide of zinc, which has a very high melting point, envelops the 
zinc in the form of a solid crust; hence the imperfect combination. 

2. When zinc is heated with cinnabar (the heat must be very strong towards 
the end of the process) decomposition takes place, with explosion, the 
sulphur combining with the zinc and the mercury volatilizing. Zino- 
filings mixed with pentasulphide of potassium withcfraw the sulphur from 
that compound, and with explosive combustion if heat be applied. 
(Berzelius.) — 3. According to Dehne, oxide of zinc, heated with sulphur, 
yields a sulphide of zinc which might easily be mistaken for blende. 
(Despretz, Ann, Chim. Phys. 33, 168.) — 4. By heating anhydrous sulphate 
of zinc-oxide with sulphur. (Vauquelin.) The mixture is heated in an 
earthen retort, first to dull redness, then more strongly; the sulphide 
of zinc produced is mixed with more or less undecomposed sulphate, 
which may be extracted by water, or completely converted into sulphide 
by again igniting the mixture with sulphur. (Gay-Lussac.) — 5. Anhy- 
drous sulphate of zinc-oxide is ignited with charcoal or in a charcoal 
crucible; if, however, a very strong white heat be applied, very little 
remains in the crucible. (Berthier.) When 100 parts of the dry salt 
are ignited in a charcoal crucible with 15 parts of charcoal, part of the 
sulphuric aci<l escapes in the form of sulphurous acid before the charcoal 
begins to act strongly, and consequently there is formed a mixture of 
sulphide and oxide of zinc, the latter of which may be extracted by 
dilute hydrochloric acid. IJP a strong white heat be applied, the residue 
amounts to only 15 per cent. (Berthier, jinn. Chim. Phys. 33, 168.) The 
more quickly the heat is raised to whiteness, the smaller is the quantity 
of oxide mixed with the sulphide. (Gay-Lnssac.j — 6. The precipitate 
formed by hydrosulphuric acid in a solution of a zmc-salt is ignited in a 
stream of hydrosulphuric acid gas. (Berzelius.) 

The native sulphide belongs to the regular system : Fig. 2, 3, 4, 6, 8, 
13, 14, and other forms. Cleavage easy parallel to d. Harder than 
calcspar. Sp. gr. 3*9 — 4*07. Transparent, pale yellow. The presence 
of other metallic sulphides gives it a red, brown, black, or green colour. 
The artificial sulphide is a white or yellowish, loosely-coherent mass. 
Sp. gr. 3*9235. (Karsten.) When prepared by (5) it is pulverulent and 
as white as the oxide. (Berthier.) Fuses only at very high tempera- 
tures : not volatile at a white heat. 



Za 

S 


.... 32-2 
.... 160 


.... 66-8 

...a Ow*« 


• ••• 

■ ••• 


AHVedson* 

66-34 
33-66 


Thomson. 

67-19 

32-81 




Proust. 

85 
15 


ZqS 


.... 48-2 


.... 100-0 


• ■«• 


100-00 


100-00 


■ l.. 


100 



c2 



20 ZINC. 

When mixed with charcoal and raised to an intense white heat, 
it volatiliices, doubtless in the form of salphide of carbon and metallic 
zinc. (Berthier.) When heated in the air, it oxidates but slowly, 
evolving sulphurous acid and forming oxide and sulphate. Completely 
oxidized by fusion with nitre. Decomposed for the most part by evapo^ 
ration with oil of vitriol. Dissolves in nitric acid, with evolution of 
nitrous gas and separation of sulphur, and in hot strong hydrochloric 
acid, with evolution of sulphuretted hydrogen. Decomposes vapour of 
water slowly at a red heat, more abundantly at a white heat, oxide of 
zinc being formed and sublimed. (Rcgnault, Ann, Chim. Phy$. 62, 380.) 
When it is heated to redness with carbonate of soda, in equal numbers 
of atoms, the mass fuses and boils, and yields a yellowish white mixture 
of sulphide of sodium, oxide of zinc, and undecomposed sulphide of zinc. 
(Berthier, Ann, Chim. Phys. 33, 167.) [For its decomposition with 
oxide of lead, see Oxide of Lead^ 

HydraJted Sulphide of Zinc, or Hydrosidphate of Zinc-oxide, — The 
white pulverulent precipitate which hydrosulphuric acid and alkaline 
hydrosulphates produce with zinc-salts. On passing hydrosulphuric gas 
very slowly through a solution of zinc-sulphate from which part of the 
zinc has been already precipitated by that gas, the sulphide is obtained, 
partly in the form of a dense mass, partly in rhombic laminiD attached 
thereto; these crystals are yellowishj not hard, and easily cloven. 
(Schindler.) When hydrochlorate of zinc-oxide mixed with excess of 
acid is precipitated by sulphuretted hydrogen, the precipitate contains 
sulphide of zinc in combination with chloride. (Reinsch, Repert, 56, 190.) 
— The white compound is converted by ignition into the yellowish 
anhydrous sulphide. The sulphide thus U)rmed is mixed, however, with 
a small portion of oxide, inasmuch as hydrosulphuric acid gas is evolved 
during ignition. (Schindler.) — Hydrated zinc-sulphide dissolves more 
readily in nitric or hydrochloric acid than the anhydrous sulphide; dis- 
solving, in fact, without the application of heat : it is also slightly soluble 
in a large excess of acetic acid. (Wackenroder, N. Br, Arch, 16, 133.) 
While yet moist, it likewise dissolves in aqueous sulphurous acid. 
(Berthier.) 

Schindler. G«iger & Reimann. 

Zn 32-2 .... 56-30 ... 570 .... 59*8 

S 16.0 .... 27-97 .... 27-9 .... 295 

HO 90 .... 15-73 .... 15*1 .... 10-7 

ZnS.HO .... 57-2 .... 10000 Z 1000 Z 1000 

The compound examined by Schindler was dried at 37 5°; that 
examined by Geiger & Reimann {Mag, Pharm, 18, 25), at 100®. Ac- 
cording to Schindler, it loses half its water at 100°, but recovers it on 
exposure to the air. 

B. OxY-suLPHXDE OF ZiNC. — When hydrogen gas is passed over 100 
parts of anhydrous sulphate of zinc-oxide ignited in a glass tube, the salt 
is quickly reduced, with formation of sulphurous acid and water; shortly 
before the end of the reduction, the majss exhibits a swelling movement 
and a glimmering light, and a small quantity of metallic zinc sublimes. 
The residue consists of 56 or 58 parts of a straw-yellow powder, contain- 
ing rather more than 1 At. sulphide of zinc to 1 At. oxide. This com- 
pound, when ignited in a stream of sulphuretted hydrogen, is converted 
into zinc-sulphide and water; hydrochloric acid dissolves it, with evolu- 
tion of sulphuretted hydrogen. (Arfvedson, Pogg, 1, 59.) 



ZINC-SULPHITE. 21 

Under this head may likewise be included the following compounds, 
which however contain a larger quantity of sulphide : a, VolzUe. Warty 
masses formed of concentric shells; of specific gravity 3'66j pale rose-rea 
or yellowish; slightly translucent. Contains: zinc-sulphide 82*82, — 
zinc-oxide 15*34, — ferric-oxide 1'84. (Fournet, Fogg, 31, 62.) — b. Fur- 
nace-calamine from a Freiberg furnace. Hollow six-sided prisms or 
laminar masses; yellow, or, if they contain sulphide of iron or other 
metallic sulphides, brown and black. Contains 4 At. sulphide of zinc to 
1 At. oxide. Gives up the latter to boiling acetic acid.' (Karsten, Schw. 
57, 186.) 

C. Hyposulphite op Zinc-oxide. — Formed by digesting aqueous 
sulphite of zinc-oxide with sulphur in close vessels. — 2. By precipitating 
hyposulphite of baryta with sulphate of zinc-oxide, and filtering. (Ram- 
melsberg.) — 3. By passing sulphurous acid gas through water in which 
freshly precipitated hydrate of zinc-sulphide is diffused: solution takes 
place with difficulty and is attended with deposition of sulphur. (Ram- 
melsberg, Pogg. 8, 442.)— 4. By dissolving zinc in aqueous sulphurous 
acid. The products are sulphite of zinc-oxide which crystallizes out, 
and hyposulphite which remains in solution. (Mitscherlich, Fogg» S, 442.) 

2Zii + 3S0« = ZnO, 80« + ZnO, S«0>. 

If the sulphnrous acid becomes very hot by acting on the zinc, sulphu- 
retted hydrogen is evolved, and a portion of the zinc is thereby re-pre- 
cipitated. (Berzelius; camp, Koene, Pogg. 63, 245.) — The crystals which 
Fourcroy & Vauquelin (Fourcroy, Systeme 5, 380) obtained by dissolving 
zinc in sulphurous acid appear to have been sulphite of zinc-oxide with a 
portion of hyposulphite suihering to it in the mother-liquid. According 
to Wohler (Jakresber, 15, 155), zinc, when digested with a saturated 
aqueous solution of sulphurous acid, forms sulphide of zinc and sulphate 
of zinc-oxide. — The salt is so easily decomposible that it cannot be 
obtained in the solid state. If the colourless and inodorous solution, 
which is not precipitated by alcohol, be evaporated at ordinary tempera- 
tures either in the air or in vacuo, white sulphide of zinc is precipitated 
at a certain degree of concentration, and trithionate of zinc-oxide remains 
in solution. (Fordos & G6lis, Compt. rend. 16, 1070; also J. pr. Chem, 
29, 228): 

2(ZnO,S50*) = ZnS + ZnO,8W. 

According to Rammelsberg, sulphur is precipitated under these circum- 
stances, and a solution of zinc-sulphate formed. 

D. Tetrathionate op Zinc-oxide. — Soluble. (Fordos & Gelis.) 

E. Trithionate op Zing-oxide. — Remains dissolved when a solution 
of the hyposulphite is evaporated. Decomposed by the slightest rise of 
temperature in the liquid; so that when aqueous hyposulphite of zinc- 
oxide is evaporated to dryness, sulphurous acid is evolved and there 
remains a mixture of sulphide of zinc, sulphur, and sulphate of zinc-oxide. 
(Fordos & Gelis.) 

F. Sulphite op Zinc-oxide or Zinc-sulphite. — Oxide of zinc 
dissolves in sulphurous acid with evolution of heat, and yields small 
crystals having a pungent, styptic taste; they are slightly soluble in 
water^ but not in alcohol. (Fourcray & Vauquelin.) The solution when 



22 



ZINC. 



eraporated yieldB pearly waloi. (A, Vogel, J, pr. Chem, 29, 280.) 
When boiled it deposits a basic salt, the solubility of which diminisbes 
as the boiling is continued. (Berthier, N. Ann. Chim, Phys, 7, 82.> The 
crystals consist of ZnO,SO^ + 2Aq. (Fordos & Gelis.) According to 
Bbttinger {Ann, Fharm. 51, 405), ignited zinc-oxide dissolves with 
difficulty in sulphurous acid, and the oxide is deposited on boiling. 

G. HyposuLPHATB OP Zmc-oxiDB.— Formed by precipitating hypo- 
sulphate of baryta with an equivalent quautity of zinc-sulphate, then 
filtering and evaporating. Indistinct crystals, having a very rough 
taste, permanent in the air, leaving 48*42 per cent, of zinc-sulphate when 
ignited, very easily soluble in water, and converted into sulphate when 
the solution is boiled. 

Cryaiallized, Heeren. 

ZnO 40-2 .... 24-19 24*25 

S«0» 72-0 .... 43-32 43-51 

6HO 54-0 .... 82-49 32-24 



ZnO,S»0» + 6Aq 1662 



100-00 



10000 



H. Sulphate op Zinc-oxide or Zinc-stjlpiiatb. — Sulphate of Zinc, 
a. Octohadc. — Precipitated on adding water to a concentrated solution 
of the bibasic sulphate. Very light precipitate, loosely coherent after 
drying. When dry, it does not absorb carbonic acid. When kept for a 
long time under a solution of monosulphate of zinc-oxide, it is converted 
into the quadrobasic salt. Resolved by gentle ignition into a mixture of 
zinc-oxide and monosulphate of zinc-oxide, which may be extracted by 
water. Not soluble in water. (Schindler, Mag, Pharm. 31, 181.) 



8ZnO 321-6 

SO* 400 

2HO 18-0 







Schindler. 


84-72 


•.«. 


84-8 


10-54 


*•.. 


10-6 


4-;4 


.... 


4-6 



8ZnO,S08 + 2Aq 379*6 



100-00 



1000 



h. Sexhasic.—VfhQTi NH»-f-ZnO,SO' is treated with water, this salt 
is left undissolved in the form of a white powder, which, when heated, 
gives off 24*12 per cent, of water and afterwards absorbs 8*4 per cent, 
from the air. (Kane, Ann. Chim. Phy$, 72, 310.) 



Anhydroui. 

6ZnO 241-2 .... 85*77 

S0« 400 .... 14-23 



Ifydrated, 

6ZnO 241-2 .... 64*98 

B0» 40*0 .... 10*78 

lOHO .... 90-0 .... 24*24 



Kane. 

.... 64*22 
.... 10*96 
.... 24-82 



6ZnO,S03 281-2 .... 100*00 



+ 10Aq 371*2 



100*00 



10000 



c. Quadrobanc.^-1. Formed by heating zinc-vitriol till it is partially 
decomposed, and boiling the residue with water. — 2. By boiling the 
aqueous solution of zinc-vitriol with metallic zinc or zinc-oxide. — 3. By 
precipitating zino-vitriol with an insufficient quantity of potash, washing 
the loosely-coherent precipitate, and dissolving it in boiling water. In 
all three cases, the solution must be filtered hot, and then the ealt will 
separate as it cools. (A. Vogel.) The second method is the surest; in 
applying the third method, only a small quantity of potash must be used; 
a larger quantity throws down a more basic salt. (KUhn, Schw. 60, 337.) 
This salt likewise ciystalliaes out, when a solution of zinc-vitriol is 



ZINC-SULPHATE. 



23 



pheed for some time in contact with metallic zino» or when a eolntion of 
the bibaaio sulphate is left to evaporate slowly in a glass with a narrow 
mouth. (Schindler.) White, shining, opaque scales (A. Vogel); long, 
softy flexible, transparent, four-sided needles, bevelled at the extremities 
like those of zino-vitriol. (Schindler.) When slowly dried it presents 
the appearance of a soft powder, greasy to the touch, — but when quickly 
dried in considerable quantities, it forms a somewhat tenacious, unctuous 
mass, having a dull and somewhat conchoidal fracture. (Kiihn.) Crystals 
of this salt which have been dried in the air give up 247 per cent. 
(8 atoms) of water between 100° and 125", without melting or falling to 
pieces, while 2 atoms remain. At a low red heat, the salt is resolved 
into oxide of zino and the monosulphate, the latter of which may be 
dissolved out by water. ^Schindler.) Scarcely soluble in water either 
cold or hot, but dissolves m a boiling solution of zinc-vitriol. (Kiihn.) 



At. 

ZnO 4 

S03 1 

HO 2 

At. 

ZnO 4 

SO» 1 

HO 8 



160*8 
400 
18-0 



73-49 

18-29 

8*22 



At. 
4 
1 
4 



b. 



160*8 
40-0 
36-0 



67-91 
16-89 
15-20 



218-8 



160-8 
40-0 
72-0 



c. 



10000 



58-95 
14-66 
26-39 



At. 

4 

1 
10 



236-8 



160-8 
40-0 
90-0 



d. 



10000 



55-29 
13-76 
30-95 



272-8 



100-00 



290-8 



10000 



According to Schindler, a is the salt dried above 100°; and d is the 
salt dried at ordinary temperatures; according to Kiihn, b is the salt 
dried somewhat above 100", and c is the salt dried at ordinary tempera- 
tures ; according to Graham {Ann, Fkarm, 29, 29), the salt has the 
composition b. 

d. Bibasic Salt, — Distdphate. — Obtained in solution: 1. By leaving a 
concentrated solution of zinc-vitriol for a considerable time in contact 
with metallic zinc or zinc-oxide. — 2. By precipitating the oxide from one 
half of a concentrated solution of zinc-vitriol, and adding the precipitate 
to the other half. The solution yields small crystals on evaporation; it 
is decomposed by rapid boiling, by slow evaporation, or by dilution with 
a large quantity of water, the salt c being deposited. It is precipitated 
by tincture of galls. Zinc-vitriol, when mixed with this salt, loses its 
tendency to crystallize. ^Schindler.) 

e, Monosulphate. — Zin(yv%triol, White Vitriol, Gallit^enstein, Viiriolum 
album 9. Zinci. — Zinc dissolves in heated oil of vitriol with evolution of 
sulphurous acid, and in dilute sulphuric acid, at ordinary temperatures, 
wiUi evolution of hydrogen. Not only does pure zinc dissolve more 
slowly than impure zmc, but according to Barrat (J. Chim, Med. 17, Q55), 
the state of aggregation has an influence on the rate of solution. Zino 
which dissolves with difficulty, ceases altogether to evolve gas if it be 
eranulated by pouring it into water while in the fused state; but if it 
be then fused again, and cast in plates, it will yield a considerable 

Quantity of gas. — 1 part of oil of vitriol diluted with 80 parts of water, 
issolves less zinc when 1 part of nitric acid is added to it than it would 
without that addition (Bigeon); according to Dobereiner {J.pr, Chem, 1, 
450), the cause of this diflerence id, that in the latter case, ammonia is 
formed, and saturates part of the sulphuric acid; hydrogen is, however, 



24 ZINC. 

always evolved, bnt if a large quantity of nitric acid be added, nitric 
oxide gas is likewise given off. Oxide of zinc combines with oil vitriol, 
producing great devolopment of heat. (Cadet, Tasckenb, 1782, 26.) 

The salt is prepared on the large scale by roasting ores containing 
sulphide of zinc, afterwards exhausting them with water, and evaporating 
the solution to the crystallizing point. By fnsion io its own water of crys- 
tallization, stirring in wooden troughs with wooden shovels till crystal- 
lization takes place, and subsequent pressing in boxes, commercial zinc- 
vitriol is made to assume the appearance of loaf-sugar. It is contaminated 
with the substances mentioned on page 6, and may be purified from all of 
them, excepting sulphate of magnesia, by the methods detailed on pages 
6 and 7. The zinc-vitriol of Goslar contains: ZnO, 15*00; MgO, 5'10; 
MnO, 3-24; FeO, 0-30; SO', 29-04; Aq. 47*00 (loss 0-32.) (Wittstein 
Repert. 55, 193.) On the small scale, zinc-vitriol is obtained by dis- 
solving zinc in dilute sulphuric acid. [For the purification, vid. pp. 
6 — 8.1 The crystals, when heated somewhat below redness, yield the 
anhydrous salt, which is white, friable, of specific gravity 3*40 (Karsten), 
and has a styptic and slightly acid taste. When ignited alone, it gives 
off anhydrous sulphuric acid, sulphurous acid, and oxygen gas, and is 
converted, first into salt c, and afterwards at incipient whiteness, into 
pure zinc-oxide. When heated to low redness with excess of charcoal, 
it gives off sulphurous acid and carbonic acid gases in the proportion of 
2 vol. SO' to 1 vol. CO^ and leaves zinc-oxide mixed with charcoal and 
traces of metallic zinc and zinc-sulphide, from which, at higher tem- 
peratures, zinc is reduced. If, on the contrary, the mixture be quickly 
heated to whiteness in a porcelain retort, it evolves at first nothing but 
sulphurous acid gas; but as soon as the heat becomes strong, the gas 
evolved consists wholly of carbonic oxide, with a small portion of carbonic 
acid, and the residue consists of sulphide of zinc. (Gay-Lnssac, Ann, 
Chim. PhyB, 63, 432; also't/^ pr, Chem. 11, Q5.) Hydrogen gas converts 
the salt at a red heat into oxysulphide of zinc. (Arfvedson.) The salt, 
when mixed with sulphur and heated in an earthen retort, first to low 
and afterwards to bright redness, gives off a large quantity of sulphurous 
acid gas, and leaves sulphide of zinc still mixed with a small quantity of 
sulphate. (Vauquelin, Gay-Lussac.) The salt, when mixed with an aqueous 
solution of sal-ammoniac, is converted into sulphate of zinc-oxide and 
ammonia, and hydrochloratc of zinc-oxide; and with solution of nitre, into 
sulphate of zinc-oxide and potash and nitrate of zinc-oxide. (Karsten.) By 
aqueous hydrochloric acid it is simply dissolved, not decomposed. (Kane.) 











Smithson- 






Anhydrous, 




Wenzd. 


Tennant. 


Thomson. 


ZnO 


.... 40-2 .... 5012 


• ••• 


4619 


.... %/v .... 


52*20 


S0» 


.... 400 .... 49-88 


• ••• 


53*81 


. .• dU .... 


47-77 



ZnO,SO» 80*2 .... 10000 .... 10000 .... 100 .... 9997 

Combinations with Water. — The salt dehydrated by ignition and 
afterwards moistened with water, combines with the water, producing 
rise of temperature. (Graham.) When exposed to air saturated with 
aqueous vapour, it takes up in three weeks rather more than 7 atoms of 
water of ciystallization. (Brandes.) If exposed to the air in summer in 
the state of fine powder, it absorbs 76*9 per cent. (7 At.) of water in the 
course of ten days, but no more afterwards. (Bliicher.) 

ft. Mono-hyarated. — Remains behind when the hepta-hydrated salt is 
dried in the air at 100®, or in vacuo over oil of vitriol at 20°. (Schindler, 



ZINC-SULPHATE. 25 

Graham.) Likewise separates in crystalline grains daring the cooling of 
a boiling saturated solution of zinc-vitriol in water. Does not part with 
its one atom of water at 205°, but gives it up when heated to about 238^ 
(Graham); at this temperature, a small quantity of sulphuric acid is 
likewise volatilized. (Thomson^ Ann. Phil, 26, 364; Schindler.) ^ 

ZnO 40-2 .... 45-07 

SOS 400 .... 44-84 

HO 9-0 .... 10-09 

ZnO,S03 + Aq 89*2 .... 10000 

/3. Bi'hydraied. — 1 . The crystals of the hepta-hydrated salt give up 
31*4 per cent, of water at 50**, and crumble to a white powder. (Schindler.) 
2. When a solution of zinc-vitriol supersaturated with sulphuric acid 
is evaporated at a temperature near 100", a crust of salt forms on its 
surface, covered with closely-packed, transparent and colourless crystals, 
which, when immersed in cold water, soon become opaque (Schindler); 
so likewise, a concentrated solution of zinc- vitriol, mixed at a boiling 
heat with sulphuric acid, yields a crystalline powder of the same com- 
position (contaminated only with adhering sulphuric acid), and this, when 
digested with alcohol of specific gravity 0*856, is converted into the 
penta-hydrated salt. (KUhn.) — 3. The powder of the hepta-hydrated salt 
is converted by boiling with absolute alcohol into a rough sandy substance 
consisting of the bi-hydrated sulphate. (Kiihn.) 

Killm. 



ZnO 

S03 

2HO 


40-2 
400 
180 


• ■•• 

■ ••• 

■ ■«• 


40-94 
40-73 
18-33 


(2) 
>.... 99-11 
41-89 
1900 


• ■■• 

• ■■• 
■ ••• 


(3) 
41-29 
41-21 
17-53 


ZiiO,SO»+2Aq. 


98-2 


• «•■ 


10000 


100-00 


• ■•■ 


100-03 



y. WUh 3^ atoms of Water, — 1. When a concentrated aqueous solu- 
tion of zinc-vitriol containing a small quantity of free acid is loft to itself 
for some time, it deposits, at 0° — besides crystals of the hepta-liydrated 
salt — the salt y in opaque rhombohedrons, which are permanent in the air 
and, when heated, give off their water without fusing. (Anthon, J, pr, 
Ghent. 10, 352; comp, Kane, ^nn. Chim. Phys. 72, 367.) 

Anthon. 

2ZnO 80-4 .... 35-D9 .... 36-00 

280» 80-0 .... 35-81 .... 3619 

7H0 63-0 .... 28-20 .... 27-81 

(ZnO,SO»+ 2Aq.) + (ZnO.SC + 5Aq.) 223*4 .... 100-00 Z. 10000 

^. Penta-hydrated, — 1. A solution of zinc-vitriol evaporated between 
40° and 50^, becomes covered with a crust consisting of this salt. (Schind- 
ler.) — 2. The finely pounded hepta-hydrated salt, boiled with alcohol of 
specific gravity 0*856, yields a uniform pasty mass, which afterwards 
solidifies into a hard crystalline substance, having a waxy fracture. 
Entire crystals of zinc-vitriol immersed in cold alcohol, slowly become 
opnque throughout their whole substance; in boiling alcohol the change 
takes place immediately. (Kiihn.) 

KUbn. Schindler. 

(2) (1) 

ZnO 40-2 .... 3211 .... 3205) -. 

S03 40-0 .... 31-95 .... 31-03; — ^* 

5HO 45-0 .... 35-94 .... 36*92 .... 36 

ZnO,SO>-h5Aq. 125'2 .... 10000 Z,. 10000 Z, 100 



26 ZINC. 

t. SeX'hydnUed. — Separates from the aqaeous solation at a temperatare 
above 30^, in oblioue rhombic prisms. A crystal of the ter-hjdrated salt 
heated aboye 52^ oecomes opaque, because it is thereby converted into an 
aggregate of small crystals of tne sex-hydrated salt. (Mitscherlich.) The 
correction mentioned in III. 238, applies here also. 

S. Hepta-hydraUd, — The ordinary form of zinc-vitriol. Separates 
from the aqueous solution at temperatures below 30^ (86° F). Large, 
transparent, colourless prisms belonging to the right prismatic system. 
Fig. 73 ; w' : « = 9P 7'; «':*»= 135^ 33'; u' : < = 134° 27'; u' : the 
face above it = 128° 58'; y : m = 120"*; i:t= 119° 23'. Cleavage 
parallel to t. (Brooke, Ann. Fhil. 22, 437.) Sp. gr. 2036. (Mohs.) The 
crystals effloresce slightly in the air; at 100% they give off 37*315 p. c. 
^6 At.) of water, and afterwards, when heated to low redness, 6 965 p. o. 
(Kiihn.) When boiling water is poured upon them, they decrepitate and 
become opaque. (Schindler.) 1 part of the crystals dissolves in 0*923 
water at 17'5^ (63'5° F.), forming a solution of specific gravity 1*4353 
(Karsten); hot water dissolves a larger quantity. Hot alcohol, also^ 
even if absolute, dissolves a trace. (Kiihn.) 

Mitscherlich. Thomson. Kiilin. 

ZnO 40-2 .... 28-071 ...„. J28-95 .«. 2802 

SO» 40-0 .... 27-93/ •"' ^^ ^^ "•* 127-64 .... 27-70 

7H0 630 .... 44-00 .... 44*76 .... 43-41 .... 4428 

ZnO,SO» + 7Aq. 143*2 .... 10000 .... 10000 .... 10000 .... 10000 

/. Bimlphate of Zinc-oxide. — Obtained by accident. Transparent, 
colourless, oblique rhombic prisms. Fig. 81, with /-face and some others, 
tt' : tt=lll°; » : tt' or m=106°; i : f 6eAinci=l 18°. Fuses when heated, 
giving off water containing sulphuric acid, and leaves, on ignition, 40 per 
cent, of monosulphate. Dissolves with difficulty in cold water^ easily in 
warm water. (Von Kobell, J. pr. Chem. 28, 492.) 

KobeU. 

ZnO 40-2 .... 19-98 .... 2000 

2S0' 800 .... 39-76 .... 3966 

9H0 81-0 .... 40-26 .... 40 34 

ZnO,2SO» + 9Aq.... 2012 .... 10000 Z 10000 

I. SuLPHOCARBONATE OF ZiNc. — Ziuc-salts give with an aqueous 
solution of sulphocarbonate of calcium, a yellowish- white precipitate, 
which^ on drying, becomes pale reddish-yeuow and translucent. (Ber- 
zelius.) 

K. Sulphide of Phosphorus and Zinc. — Sulphide of zinc, obtained 
by precipitating a zinc-salt with hydrosulphato of ammonia, and igniting 
the precipitate in a current of hydrosulphnric acid gas, is placed in the 
first of two bulbs blown upon a glass tube, then moistened, by means of a 
pipette, with liquid protosulphide of phosphorus, and very cautiously 
heated in a cnrrent of hydrogen gas, till the excess of sulphide of phos- 
phorus is expelled. If the red mass should turn white from heating too 
strongly, the whole must be left to cool till the sulphide of phosphorus 
has again penetrated the mass, and then the heat may be again applied. 
( Vid. IL, 215.) — Fine red powder of the colour of minium. Resolved by 
distillation below a red heat into sulphide of phosphorus which passes 
over in the form of a pale-yellow liquid, and white zinc-sulphide which 



ZINC AMD SELENIUM. 27 

remains behiod. Takes fire readily, and when finally heated to redness^ 
leaves ordinary monophosphate of zinc-oxide in a state of fusion. Dis- 
solves in hydrochloric acid with copions evolution of sulphuretted 
hvdrogen, and separation of red pulverulent l^sulphide of phosphorus. 
(Berzelius, Anri* Pharm, 46^ 150.) 

BerzeHuB. 

2Zn8 96-4 .... 43-31 .... 45 

3P 94-2 

28 32-0 



■ •■• 



42-32) 
14-37f 



•••• 



55 



2ZnS,FS» 222-6 .... lOOOO .... J 00 



Zinc and Selenium. 

A. Selbnide op Zinc. — These elements combine but venr imperfectly 
when fused together, the greater part of the selenium volatilizingi and a 
mere film of sulphur-yellow selenide of zinc being formed on the surface 
of the metal; but the combination takes places easily and with explosion^ 
when vapour of selenium is passed over zinc at a red heat. — Lemon- 
yellow, pulverulent. — Cold dilute nitric acid dissolves the zinc, with 
evolution of nitrons gas; the selenium, which separates in the first 
instance, is afterwards dissolved, on the application of heat, in the form of 
selenious acid. (Berzelins.) 

Hydraied Selenide of Zinc, or HydroseUniate of Zinc-oxide, — Aqueous 
hydroseleniate of potash gives with zinc-salts a pale-red precipitate, 
which, on exposure to the air, assumes a darker red colour from decompo- 
sition of the hydroselenic acid; it is insoluble in water. (Berzelius.) 

B. Selenite op Zinc-oxidb. — Monoielenite, White powder, inso- 
luble in water. When heated, it gives off water, and fuses to a yellow 
transparent liquid, which on cooling forms a white mass, having a 
crystalline fracture. At a low white heat, it enters into ebullition, and 
is converted, with sublimation of selenious acidj into an infusible basic 

salt^ no longer decomposible by heat. 

Mnspnttt. 

ZnO 40-2 .... 49-12 

SeO^ 560 .... 35-08 

2H0 180 .... 15-80 .... 16-66 

ZnO,SeO» + 2Aq. 114*2 .... 100*00 

6. Biedeniie, — By dissolving a in selenious acid. Transparent, 
fissured, gummy mass, easily soluble in water. (Berzelius.) 

IT c. Quadro9elenite. — ^^^hen dean zinc-tnmings or plates of zinc are 
immersed in a somewhat concentrated aqueous solution of selenious acid, 
the metal soon becomes covered with a thin red layer of reduced 
selenium, and a solution is formed containing qnadroselenite of zinc-oxide. 
This solution, when evaporated to a syrupy consistence in vacuo over oil 
of vitriol, and the a left at rest for about a week, yields the salt in large 
yellow crystals very much like those of monochromate of potajsh. Oblique 
rhombic prisms, having their terminal edges and frequently also the obtuse 
lateral edges replaced by planes: generally associatea in macled crystals. — 
Permanent in tne air, soluble in water. Solution colourless; has a strong 
sour taste; not decomposed by acids. Becomes turbid when heated, the 
salt being resolved into selenious acid and neutral zino-selenite. A 



28 ZINC. 

crystal heated to 30^ or 40^^ undergoes tbe same change, becoming white 

and opaque ; on increasing the heat, the crystal fuses, and is resolved 

into water which distils over, seleuious acid which sublimes, and a neutral 

or baaic salt which remains behind. 

Wohler. 

ZnO 40-2 .... 13-97 .... 14-86 

4Se03 224-0 .... 76 72 .... 7603 

3H0 270 .... 9-31 .... 910 

ZnO,4S€0> + 3Aq 291-2 .... 100-00 Z 9999 

May be regarded as a double selenite of zinc and watep : thus — 

ZqO, 4Se02 + 3HO = ZaO, SeO* + 3H0, SeO'. 
(Wohler, Ann. Fkarm. 59, 279.) 1 

C. Seleniate op Zinc-Oxide. — ZnO,SeO'+7Aq. The crystals of 
this salt, which belong to the square prismatic system, are isomorphous 
with those of sulphate and seleniate of nickel-oxide. Fig. 37; e:e''=z 
138° 53'; cleavage parallel to the truncation-face j9. (Mitsoherlich, Fopj, 
12, 144.) 

Zinc and Iodine. 

A. Iodide of Zinc. — Zinc and iodine combine readily and with 
slight evolution of heat, producing a colourless, easily fusible substance, 
which, when heated, sublimes in beautiful four^sided needles. (Gay-Lussac.) 
From an aqueous solution evaporated by heat, and afterwards cooled, the 
iodide of zinc separates in octohedrons (Berthemot, J. Fharm, 14, 610); 
and by slow evaporation over oil of vitriol in a receiver containing air, it 
crystallizes in anhydrous cube- octohedrons. (Rammelsberg, Fogg, 43, 665.) 
When heated in the air, it gives off iodine vapour, and is converted 
into oxide of zinc. (Gay-Lussac.) When exposed to the air at ordinary 
temperatures, it absorbs water and oxygen, and is decomposed. (Buckner, 
Fepert. 66, 204.) With oil of vitriol it yields sulphurous acid, iodine, 
and sulphate of zinc-oxide. With the iodides of the alkali-metals, it 
forms rapidly deliquescent crystals. 

Rammelsberg. 

Zn 32-2 .... 20-35 .... 20-347 

I 1260 .... 7905 

Znl 158*2 .... 100-00 

Aqueous Iodide of Zine or Hydriodate of Zinc-Oxide. — Iodide of zinc 
deliquesces in the air. The same solution is formed by keeping zinc and 
iodine immersed in water till the liquid loses its colour. — Colourless, 
somewhat acid liquid, containing 24 per cent, of zinc-oxide to 76 per cent, 
of hydriodic acid. (Gay-Lussac.) The highly concentrated solution 
[overcharged with oxide?] when diluted with water, deposits hydrated 
zinc-oxide free from iodine. (Rammelsberg.) 

B. OxY-ioDiDE OP Zinc— If the liquid obtained by long digestion of 
zinc with iodine and water, be filtered hot, it becomes turbid on cooling, 
and deposits this compound. (W. Miiller, J, pr. Chem., 26, 441.) 



ZINC AND BROMINE. 29 

C. Aqtieous Bintodide of Zinc or Hydriodite of Zinc-oxide, — The 
aqueous solution of protiodide of zinc dissol\res as mucb iodine as it 
already contains, and acquires a brown colour. (Baup.) 

D. Iodide of Zinc-oxide ? — Zinc-oxide heated to 200^ in contact with 
iodine, takes up a certain quantity of that substance, but gives it up again 
on being treated with an acid. (Grouyelle.) 

E. loDATE OF ZiNC-oxiDE or ZiNC-iODATE. — Aqueous iodic acid acts 
upon zinc with effervescence at first, but the effervescence soon ceases in 
consequence of the formation of a diflicultly-soluble salt. (Gonnell, 
i^. Edinh, Phil. J. 11, 72.) Iodic acid and iodate of potash precipitate 
zinc-sulphate after a while. (Pleischl.) — The salt is prepared by mixing a 
solution of 1 At. ordinary zinc-sulphate with 1 At. iodate of soda, evapo- 
rating to dryness, and extracting the sulphate of soda with water. 
(Rammelsberg, Pogg,^ 44, 563.) — Small crystalline grains, or crystalline 
powder. When heated, it gives off iodine vapour and oxygen gas, and 
yields a sublimate of somewhat needle-shaped iodide of zinc, leaving a 
residue of zinc-oxide, mixed with a very small quantity of iodide which 
may be extracted by water. (Rammelsberg.) Fuses and detonates 
slightly on red-hot coals. (Berzelius.) Dissolves in 114 parts of water at 
15^, and in 76 parts of boiling water. Soluble in nitric acid and in 
ammonia. (Rammelsberg.) 

CryztaUiztd, Rammelsberg, 

ZnO 40-2 .... 17-93) Q.-g 

lO* 1660 .... 74-04i' • ^^ '*• 

2HO 18-0 .... 8-03 .... 8-22 

ZnO,IO» + 2Aq 224-2 .... 100*00 Z 10000 



Zinc and Bromine. 

A. Bromide of Zinc. — Zinc and bromine do not combine even when 
the metal is heated, and the bromine dropped upon it. (Lowig.) — 1. The 
bromide is obtained by passing bromine vapour over red-hot zinc till the 
metal is converted into a colourless liquid. (Berthemot.) — 2. By dissolving 
zinc in aqueous hydrobromic acid, the solution being attended with evolu- 
tion of hydrogen. (Balard) — evaporating to dryness — and subliming the 
residue. (Lbwig.) — Sublimes in white needles, which fuse into a light 
yellow liquid (Lowig); colourless, according to Berthemot. Taste, sweet 
and styptic. Decomposed by nitric acid. (Berthemot.) 

Berthemot. 

Zn 32-2 .... 29-11 2925 

Br 78-4 .... 70-89 70'75 

ZnBr 110-6 .... 100-00 ZZ 100*00 

Hydrated Bromide of Zinc or Hydrohromate of Zinc-oxide. — Bromide 
of zinc deliquesces rapidly in the air (Lbwig), and becomes strongly 
heated by contact with water. (Berthemot.^ The colourless soiution 
yields small crystals on evaporation. (Lowig.) When evaporated till a 
film of salt forms on its surface, it solidifies in a mass of indistinct crystals 
on cooling. (Berthemot.) When evaporated in vacuo, it does not yield 
crystals, but solidifies to a very deliquescent mass, presenting an app^r- 
ance of efflorescence on the surface. (Rammelsberg.) — Bromide of zinc 



80 ZINC. 

dissolves in ammonia^ hydroohlorio acid^ aoetio aoidy alcohol, and ether. 
(Berthemot.) 

Bromine- water slowly dissolves a small quantity of sine-oxide; the 
solution has no bleaching power, but contains bromide of zinc and bromate 
of zinc-oxide. (Balard, /. pr, Chem.j 4, 177.) 

B. Bromate of Zinc-oxide, or Zimo-Bromate.—- By dissolving car- 
bonate of zinc-oxide in aqneons bromic acid, and evaporating, octohedrons 
with cube-faces are obtained, which are permanent in the air. The 
crystals effloresce in vacuo over oil of vitriol. They fuse at 100°, but 
do not part with all their water of crystallization till they are heated to 
200°, at which temperature, moreover, they are completely resolved into 
bromine vapour, oxygen ^as, and veiy loosely coherent oxide of zinc. They 
dissolve in their own weight of cold water. (Rammelsberg, Pogg. 52, 90.) 



ZdO 


40*2 

118-4 

540 


.... 18-91 
.... 55-69 
.... 25-40 


•••• 


Rammelsbeii;. 
16-44 


BrO» 

6HO 


58-31 
25-25 






ZnO,BrO* + 6A(i. 


212-6 


.... 10000 


•.•• 


100-00 



Zinc and Chlorinb. 

A. Ghloridb op Zinc. — Butter of Zinc, Butyrum ZincL — 1. Thin 
laminse of zinc introduced into chlorine gas at ordinary temperatures 
bum with a white light and form chloride of zinc. (H. Davy.) Zinc 
heated nearly to its melting point in a current of dry chlorine gas, absorbs 
the chlorine, with vivid emission of sparks. (Berzelius.) — 2. The chloride 
is also formed by heating 1 part of zinc filings with 2 parts of corrosive 
sublimate. (Pott.) — 3. By evaporating to dryness an aqueous solution of 
zinc-chloride prepared as described below, and heating the residue to 
redness in a glass tube with narrow aperture. (J. Davy, Schw. 10, 331.) 
At the very high temperature required to dehydrate the salt completely, 
hydrochloric acid is driven ofi*, and a portion of zinc-oxide remains mixed 
with the chloride. (Mousson, Ann. Chim, Phys,, 69, 240.) — 4. By evapo- 
rating the solution to dryness, and heating the residue in a retort till the 
chloride of zinc distils over. (Pott, Brandt.) — 5. By distilling 1 part 
of zinc-oxide with 2 parts of sal-ammoniac, the receiver being charged 
after a while. (Lesage.) — 6. By distilling dehydrated zinc-vitriol with 
its own weight of common salt. {CreU Ghent. «/., 1, 116.) 

Whitish-grey, semi-transparent, soft like wax; fuses, according to 
H. Davy, somewhat above 100°; according to J. Davy, just below dull 
redness, and on cooling becomes first viscid, and then solid. Sublimes in 
white needles at a white heat. Has a burning and nauseating taste even 
when dilute. (Papenguth.) — When heated in phosphuretted hydrogen gas, 
it yields hydrochloric acid gas and phosphide of zinc. (H. Rose.) — With 
cold oil of vitriol, it suddenly gives off all its hydrochloric acid, and 
leaves sulphate of zinc-oxide. (A. Vogel.) Forms definite compounds 
with sal-ammoniac and chloride of potassium. 

J. Davy. 

Zn 32*2 .... 47*63 .... 50 

CI 35-4 .... 52-37 .... 50 



On 


Wenxel. 


2n0 


40-2 .... 60-47 .... 57*56 


Cl-O.... 


27-4 .... 40-53 .... 42-44 



ZnCl.... 67-6 .... 100-00 .... 100 67-6 .... 10000 .... 10000 



OXYCHLORIDB OF ZINC. 31 

Hydrated Chloride of Zinc or Hydrochlorate of Zinc-oaide, — Chloride 
of zinc deliquesces in the air. — Zinc dissolves in aqueous hydrochloric 
acid, hydrogen gas being evolved and a colourless solution formed. 
(Sch. 9.) A solution of zinc-sulphate may also be precipitated by 
chloride of calcium, the filtrate concentrated by evaporation, and the 
remaining liquid separated from the precipitated gypsum. (Papengath^ 
Schw. Ann. 2, 143.) — The solution, evaporated to a syrupy consistence, 
and mixed with a small Quantity of strong hydrochloric acid (because it 
ffives off some of its acid during the evaporation) yields small, highly 
deliquescent octohedrons. (Schindler.) 

CrpiialltMed. Schindler. 

Zn 32-2 .... 42-04 .... 3980 

CI 35-4 .... 46-21 .... 43-81 

HO 9-0 .... 11-75 .... 16-39 

ZnQ + Aq 76-6 .... 10000 .... 10000 

Protoxide of tin, hydrated oxide of lead, and protoxide of mercary, 
added to a boiling aqueous solution of hydrochlorate of zinc-oxide, preci- 
pitate all the zinc in the form of oxychloride. (Demar9ay, Ann, Phar. 
11, 251.) 

B. Oxychloride of Zinc or Basic Hydrochlorate of Zinc-Oxide. 
— «. When aqueous chloride of zinc is evaporated to a syrupy consis- 
tence, hydrochloric acid is given off; and the syrup, on subsequent cool- 
ing, solidifies in a gelatinous mass, probably from separation of a still 
more basic salt, which always re-dissolves when heated. Water added to 
the syrup throws down a wbite bulky precipitate, and the filtered liquid 
gives a precipitate with tincture of galls. (Schindler.) A similar solution 
precipi table by water is obtained by saturating warm concentrated hydro- 
chloric acid with oxide of zinc. 

h. ZnCl,dZnO. — 1. Formed by boiling a concentrated solution of 
chloride of zinc with oxide of zinc, and filtering; the compound is depo- 
sited on cooling. — 2. By precipitating hydrochlorate of zinc-oxide with 
an insufficient quantity of ammonia, and digesting the precipitate in the 
liquid. By (1) fine pearly octohedrons; by (2) soft, white powder. 
Dissolves sparingly in water, more abundantly in aqueous chloride of 
zinc, easily in aciois and in caustic ammonia or potash. (Schindler, Mag^ 
Fharm. 36, 45.) 

Schindler. 

ZnCl 67-6 .«. 32-78 32-5 

3ZnO 120-6 .... 5849 58 8 

2H0 18-0 .... 8-73 8-7 

ZnCl,3ZnO + 2Aq 206*2 .... 100-00 1000 

The compound analyzed by Schindler appears to have been dried at 100^; 
the compound dried at 88° contains 4 At. water. (Kane.) 

c, ZnC],6ZnO. — 1. Separates in the decomposition of NH^,ZnGl or 
of NH^,2ZnCl by water. — 2. Precipitated on adding ammonia to the 
aqueous solntion of chloride of zinc, till a portion of the precipitate is 
re-dissolved. — White, tasteless powder, insoluble in water. Gives off 
water and chloride of zinc when ignited, and leaves a residue, from 
which water extracts chloride of zinc, leaving a compound containing a 
larger proportion of oxide. (Kane, Ann. Chim^ Phy$. 72, 296.) 



32 ZINC. 



Dried at 82''. 








Kane. 


ZnCl 


67-6 


• «•• 


18-63 


19-13 


6ZnO 


241-2 


• •■• 


66-48 


65-85 


6HO 


54 


• • • • 


14-89 


1502 


ZnCl. 6ZnO + 6Aq 


362-8 


• •■• 


100-00 


10000 



The compound^ when dried at ordinary temperatures, contains 23*5 per 
cent. (10 At.) of water; when dried at a high temperature, it absorbs 
from the air 1 5 per cent. (4 At.) of water, which cannot be driren out 
at 100°. (Kane.) 

d, ZnCl,9ZnO. — 1. Precipitated on diluting the syrup a with water. 
— 2. By precipitating aqueous zinc-chloride with an insufficient quantity 
of ammonia and filtering immediately: the compound thus formed con- 
tains, however, a small quantity of ammonia. (Schindler.) — 3. By adding 
potash to aqueous zinc-chloride, till the mixture begins to exhibit an alka- 
line reaction. (Kane.) — Yerj soft, white powder. Not perfectly freed from 
chlorine by boiling with carbonate of potash. Converted into the compound 
h by digestion with aqueous zinc-chloride. Insoluble in water, less 
soluble in ammonia than 6, but easily soluble in acids. (Schindler.) 



ZnCl 67-6 

9ZnO 381-8 

3H0 27-0 





Schindler. 


14-81 


14-41 


79-27 


79-88 


5-92 


5-71 



ZnCl,9ZnO + 3Aq 456-4 .... 10000 10000 

The salt obtained by (3) contains 5*92 per cent, of chlorine, and 22-68 
(14 At.) water; after perfect drying, it absorbs 4 atoms of water from 
the air. 

G. Hypochlorite of Zinc-oxide or Zinc-hypochloritb.— The solu- 
tion of zinc- oxide in aqueous hypochlorous acid, decomposes sponta- 
neously, if it contains excess of acid, into chlorine gas, chloride of zinc, 
and chlorate of zinc-oxide; and even when the zinc-oxide is in excess, 
the solution cannot be evaporated without decomposition. When heated, 
it gives ofi* hypochlorous acid, probably mixed with a small quantity of 
free oxygen, and deposits a white, pearly oxychloride, which decomposes 
spontaneously into chloride of zinc, chlorate of zinc-oxide, oxygen gas, 
and a small quantity of chlorine gas. (Balard.) Zinc>vitriol mixed with 
excess of hypochlorite of lime, gives a precipitate consisting of zinc-oxide 
and sulphate of lime, and a liquid which contains no zinc-oxide, but 
hypochlorite of lime with excess of acid. (Balard.) — I At. chlorine in 
the state of aqueous solution dissolves 1 At. oxide of zinc. The trans- 
parent and colourless solution bleaches tincture of indigo strongly, even 
after a quarter of an hour's boiling. (Grouvelle, Ann. Chim. Fhyi. 17> 
37.) The solution is resolved by distillation into hypochlorous acid^ 
which passes over in small quantity, chloride of zinc which remains dis- 
solved, and oxychloride of zinc which separates in the solid state. 
(Balard.) 

D. Chlorate OF Zinc oxide or Zinc-chlorate.— 1. Formed by dis- 
solving carbonate of zinc-oxide in aqueous chloric acid. Metallic zinc 
dissolves in the acid without any [or with slight] effervescence, and 
forms hydrochlorate and chlorate of zinc-oxide. — 2. By passing gaseous 
fluoride of silicium through water in which finely divided carbonate of 



ZINC AND NITROGEN, 3S 

xinc-oxide is diffused — boiling the filtered liquid with an equivalent 
Quantity of chlorate of potash — and filtering from the precipitated silico- 
nuoride of potassium. (0. Henry, J, Pharm, 25, 269.) — Chlorate of zinc- 
oxide crystallizes apparently in octohedrons; tastes very rough. — When 
thrown on red-hot coals^ it is decomposed, with a yellowish light, but 
without actual detonation. In contact with sulphuric acid it assumes a 
yellowish colour, and emits an odour of chloric oxide, but does not preci* 
pitate a solution of nitrate of silver. Soluble in water and alcohol. 
(Vauquelin, ^nn. Ckim. 95. 118.)— Contains ZnO, CIO* 4-6 Aq. (Wachter, 
J. pr. Ckem. 30, 321.) 

E. Perchlorate of Zinc-oxide or Zinc-perghlorate. — 1. By 
precipitatinfi^ perchlorate of baryta with zinc-vitriol, and concentrating 
by evaporation. (Serullus, Ann. Chim. Fkys, 46, 305.) — 2. Obtained like 
chlorate of zinc-oxide, method 2. The carbonate of zinc precipitated by 
excess of carbonate of soda from 5 parts of zinc-vitriol, is to be treated, 
after conversion into silico-fluoride of zinc, with 4 parts of perchlorate 
of potash. The filtrate, when evaporated to a syrup, and then left in a 
warm place, deposits crystals. iO, Henry.) — Prisms united iu tufts; 
deliquescent; soluble in alcohol, (SeruUas.) 



Zinc and Fluorine. 

A. Fluoride of Zinc. — Hydrofluate of potash mixed with solution 
of zinc-vitriol produces a gelatinous precipitate, which by drying is con- 
verted into a white tasteless powder. The same compound is obtained 
by digesting aqueous hydrofluoric acid with excess of zinc. (Gay-Lussac 
and Thenard.) From its solution in aqueous hydrofluoric acid, this com- 
pound separates, on evaporation, in small, white, opaque crystals, having 
the taste of zinc-salts. It dissolves sparingly in pure water, somewhat 
more freely in water containing hydrofluoric acid, and likewise in nitric 
or hydrochloric acid; easily in aqueous ammonia. With the fluorides of 
the alkali-metals, it forms colourless, sparingly soluble compounds. 

Aqueous Hydrofiuaie of Zinc-Jluoride or A cid Hydrofluate of Zinc- 
oxide. — Formed by dissolving fluoride of zinc in aqueous hydrofluoric 
acid, or by dissolving zinc in excess of aqueous hydrofluoric acid, the 
reaction being attended with evolution of hydrogen. (Scheele, Gay- 
Lussac and Thenard.) 

B. Fluoboridb of Zinc or Hydrofluate of Boracic acid and 
Zinc-oxide. — ^ZnF,BF'. — By dissolving zinc in aqueous hydrofluoboric 
acid (II, 364) till no more hydrogen is evolved at ordinary temperatures. 
The solution, when evaporated, leaves a syrup, which solidifies on cooling 
and deliquesces when exposed to the air. 



Zinc and Nitrooen. 

A. Nitride of Zinc? — A long glass trough contains water and 
pieces of sal-ammoniac; into one end of this trough there dips a platinum 
wire connected with the negative pole of a six-pair Grove*s battery; 
into the other, a ball of zinc connected with the positive pole. A spongy, 
foliated mass, of the colour of graphite, then collects on the negative 

YOL, V. D 



34 ZING. 

wire; ibis maes growB^ and rises to the sarfiuse from tlie buoyancy of the 
adherin/^ gas-babblee. "When washed with water on the filter, and then 
dried at a gentle heat, it appears grey, without metallic lustre; has a 
density of 4*6, and conducts electricity. — 5 grains of this substance yield, 
when ignited, 0'7d cub. in. of a mixture of ^tween 3 and 4 vol. nitrogen 
gas to 1 vol. hydroffen. The last portions of gas evolved appear to 
consist chiefly of hydrogen, derived apparently from the deoomposition 
of the adhering water: for moisture is likewise deposited in the tube« 
The ifl^ited residue exhibits contraction, but without change of colour.--* 
Nitride of zinc dissolves like zinc in aqueous acids, but the hydrogen 
evolved contains a small quantity of nitrogen. (Grove, Fhil. Mag. J, 1 9, 
98; also F(^g. 54, 101.) 

fi. Nitrate of Zino-oxidb, or Zino-kitratb.— -a. Octobasie. — Formed 
by heating the salt c till it becomes nearly solid. (Gruuvelle, Ann. Chim. 
fhys. 19, 137.) The salt c, when heated till part of the acid is driven 
oflT, retains its transparency at first. [The mass dissolves partially on 
cooling, leaving a white residue consisting of a basic salt.] If a larger 
quantity of acid be driven off, the melted mass appears turbid ; and if 
treated with water after cooling, leaves a yellowish residue, consisting 
of the salt a, (Schindler.) — 2. By precipitating the salt c with an insuN 
ficient quantity of ammonia. (Grouvelle.) The precipitate contains a 
small quantity of ammonia. (Schindler.) 

Orouvelle (1.) Sdiindler (1.) Gronvelle (2.) 

82nO 321'6 .... 81-71 .... 81-69 .... 81*70 .... 7813 

NO* 54-0 .... 13-72 .... 1375 .... 1376 .... 1313 

2HO 18-0 .... 4-57 .... 4*56 .... 4-54 .... 874 

8ZnO,NO» + 2Aq. 3936 .... 100-00 .... 10000 .... lOO'OO .... 10000 

The salt obtained by (2) contains 4 At. water. (Grouvelle.) 

h, Quadrobatic, The salt a digested with the solution of e swells 
up, turns white, and forms a loose powder when dry. (Schindler.) 



4ZnO 

NO» 

2HO 









Schindler. 


160-8 


...a 


69-07 


68-90 


54 


.... 


23-19 


23-41 


180 


.... 


7-74 


7-69 



42nO,NO» + 2Aq 232*8 .... 10000 10000 

The aqueous solution of c, boiled with oxide of zinc, does not take up 
any of that compound. (Schindler.) 

IT Gerhardt has obtained a basic nitrate of zinc-oxide which crystal- 
lizes in prismatic needles, and contains 4ZnO,NO' + dHO. {J, Fharm* 
3* ser. 12, 61.) t. 

c. Mononitrate, Nitric acid rapidly dissolves zinc, producing great 
heat, and evolving nitrogen, nitrous oxide, and nitric oxide. (II. 374 and 
397.) The salt crystallizes from very concentrated solutions in trans- 
parent, colourless, flattened, striated, four- sided prisms, with four-sided 
summits : it has a styptic taste. Fuses when heated, and at 100'' gives 
off 28 p.c. (3 At.) water; the remaining 3 atoms are not evolved till a 
temperature is attained at which the nitric acid itself is driven off. 
(Graham.) The acid is first evolved in its entire state, together with 
the water; afterwards in the form of hyponitrio acid vapour and oxygen 



ZINC-OXIDE WITH AMMONIA. 35 

gas. (Schindler.) Detonatee with a red flame on glowing coals. Deli- 
quesces in the air; dissolves readily in water and alcohol. Hydrated 
oxide of lead boiled with the solution precipitates the zinc completely in 
the form of a basic salt. (Demar^ay.) 

Cfytiallized. Graham. Schind'er. 

ZnO 40-2 .... 2712 26-94 .... 25*6 

NO» 64-0 .... 36-44 .... 34-5 

6HO 54'0 .... 3fi-44 .... 399 

ZnO, NO* + 6Aq! 148-2 .... 10000 ZZ .... 100*0 

According to Graham {Ann, Pharm. 29, 17) and Millon {Compt, 
rendA 4, 905), the crystals contain 6 At. water; Schindler*s analysis 
gives 7 atoms. 

C. Zinc-oxide with Ammonia. — 1. Hydrated zinc-oxide dissolves 
easily in aqueous ammonia. The ignited oxide does not dissolve at all 
in ammonia, according to Fimhaber; according to Schindler, it is but 
very sparingly soluble, but its solubility is greatly increased by traces of 
different ammonia and potash salts. The most efficient salts in this 
respect are the phosphates; then follow the arseniates, hydrochlorates, 
sulphates, nitrates, acetates, carbonates, tartrates, citrates, and, lastly, 
the sulphites. Succinic and benzoic acid favour the solution only when 
the ammonia is very dilute ; boracic, hydriodic, chloric, arsenious, oxalic, 
and gallic acid, when digested with zinc-oxide and ammonia, do not pro- 
mote the solution of the oxide, but combine with it, together witn a 
small quantity of ammonia. For instance, on adding to ammonia in 
which zinc-oxide .is diffused, a few drops of phosphate of ammonia or 
potash, the zinc-oxide is immediately dissolved, especially if heat be 
applied. (Schindler.) Hence may perhaps be explained the fact observed 
by Fimhaber (Schw, 42, 246), viz, that zinc-oxide precipitated by 
ammonia from a solution of the sulphate [the precipitate contains 
sulphuric acid], dissolves readily in ammonia, even after ignition. — 
2. Zinc immersed in ammonia and placed in contact with iron dissolves 
slowly, with evolution of hydrogen, and forms the compound under con- 
sideration. (Runge.) By this process, without any admixture of acid, 
a highly concentrated solution may be obtained; 100 parts of such a 
solution^ which, after the removal of the metallic iron and zinc, had 
already deposited crystals of hydrated zinc-oxide, was found to contain 
d'95 parts (I At.) zinc-oxide to 7 '68 parts (rather more than 4 At.) 
ammonia. (Schindler.) The zinc likewise dissolves without the presence 
of the iron, but more slowly. The solution is colourless; if concentrated, 
it becomes turbid on dilution with a considerable quantity of water. The 
solution obtained by (2) may be mixed with 15 times its bulk of water 
without producing turbidity, but with a larger quantity of water, it 
gives a coagulated, and with a still larger quantity, a pulverulent preci- 
pitate. (Schindler.) The solution (1), when it evaporates in the air, 
yields needles [probably consisting of carbonate of zinc-oxide and 
ammonia], and, when evaporated in the sand-bath, leaves an inodorous 
mass, soluble in water, and evolving ammonia when treated with potash. 
(Wittstein, Repert, 57, 60.) The solution, when evaporated, leaves oxide 
of zinc containing small quantities of ammonia and carbonic acid. 
(Bonnet.) Baryta, strontia, and lime-water added to the solution throw- 
down a portion of the zinc-oxide in combination with the earthy alkali. 
(BerzeliuB.) 



36 ZINC. 

D. Carbonate op Zinc-oxide and Ammonia. — Zinco-ammonic 
CarboncUe. — a. 1. Zinc-filings and oxide of zinc dissolve readily in 
aqueous carbonate of ammonia, the former with brisk effervescence, the 
latter with evolution of heat. The solution yields, on evaporation, white 
crystals having a silky lustre. The saturated solution is rendered turbid 
by excess of water, and gives a white precipitate with acids, and a grey 
precipitate with tincture of galls. (Lassonne, CrelL Chem. J. 5, 59; 
Koloff, A. GM. 6, 443.) The solution becomes somewhat turbid on 
dilution with water, in conseouence of the precipitation of a compound 
[probably 6] richer in oxide. (Bonnet.) — 2. When hydrochlorate of 
zinc-oxide is dropt into excess of ammonia, then carbonate of ammonia 
added, and the mixture exposed to the air, there are formed, as the 
ammonia evaporates, needle-shaped crystals united in stellated masses, 
insoluble in water, and having a strong ammoniacal odour ; they turn 
milk-white in the air, and continue to evolve ammonia till they are 
converted into the following compound b. (Wohler, Pogg. 28, 616.) 

b. White powder, which, when heated, evolves a large quantitjr of 
water and carbonate of ammonia, and leaves 62*2 per cent of zinc-oxide. 
(Wohler.) When zinc-oxide in excess is digested with aqueous carbonate 
of ammonia, a crystalline powder is obtained. (Bonnet.) 

E. Boride of Nitrogen and Zinc ? — 2 parts of vitrefied boracic acid 
and 5 parts of cyanide of zinc heated to whiteness for an hour in a closed 
charcoal crucible yield a whitd mass. This mass imparts a green colour 
to the outer blowpipe flame, but without melting; bums with a pale blue 
liffht when thrown into fused chlorate of potash; gives off a large quantity 
of ammonia when heated with hydrate of potash; and is not decomposed 
by chlorine, even at a red heat. (Balmain, Phil. Mag, «/. 21, 270.) 

F. Ordinary Phosphate op Zing-oxide and Ammonia. — ZincO' 
amnionic Phosphate, — Formed by adding a solution of ordinary phosphate 
of ammonia mixed with excess of ammonia to a solution of zinc-vitriol, 
and digesting till the precipitate has lost its flocculent character- and 
become crystalline, and the excess of ammonia is evaporated — then 
washing the precipitate, pressing it between folds of bibulous paper, and 
drying it. Instead of phosphate of ammonia, phosphate of soda mixed 
with ammonia may be used, but then the washing is difficult. White 
powder, which, on ignition, yields 79*33 per cent, of zinc-oxide. Insoluble 
m water, but soluble in acids, ammonia, potash, and soda. (Bette, Ann, 
Pharm. 15, 129.) 

Calculatwn 1. 

NH» 17-0 .... 8-68 

2ZnO 80-4 .... 41-06 

cPO» >,^ 71-4 .... 36-47 



3H0 4 27-0 .... 13-79 

NH^O,2ZnO,cPO» + 2Aq 1958 .... 100-00 

Calculation 2. Bette. 

NH» 17-0 .... 7-20 8-65 

3ZnO 120-6 .... 51-10 47-55 

cPO» 71-4 .... 30-26 31-78 

3H0 270 .... 11-44 12-02 



NH^O,3ZnO,cPC)* + 3Aq. 2360 .... lOO'OO 10000 

Calculation 1 corresponds to the manganese-salt (IV. 232) ; calculation 2, 
which Bette prefers, corresponds to the arseniate (V. 50); neither of them 
agrees exactly with the analysis. 



QUADROBASIC ZINC-SULPHATE WITH AMMONIA, 37 

Q, Ptrophosphate of Zinc-oxide and Ammonia. — ZtTieo-ammonic 
Pyrophosphate, — Formed by mixing hydrochlorate of zino-oxide with a 
sufficient quantity of sal-ammoniac to' prevent precipitation by ammonia, 
and then sulding a mixture of ammonia and pyrophosphate of soda. The 
precipitate must be washed till the water no longer renders a silver- 
solution turbid, then pressed between paper, and dried. If the same 
process be used as for salt F, with the substitution of pyrophosphate of 
soda for the ordinary phosphate, the resulting precipitate will contain too 
much zinc-oxide and too little phosphoric acid to exhibit any stoichio- 
metric relation. The precipitate formed by the first-mentioned process 
has the appearance of loose flakes. When ignited, it leaves 79*3 per 
cent, of zinc-phosphate. Contains in 100 parts — ammonia, 5*78; zinc- 
oxide, 42*43 j pjrrophosphoric acid, 37*31; water, 14*78, — corresponding 
to the formula, 2NH' + 6ZnO -f- 36PO* + 9aq. (Bette.) 

H. Metaphosphate op Zinc-oxide and Ammonia. — Zinco-ammonic 
Metaphosphate. — Zinc-vitriol mixed with ammonia is precipitated by a 
solution of vitreiied metaphosphate of soda, likewise mixed with ammonia. 
A white precipitate is immediately formed, and subsequently coagulates 
in a resinous mass. When diy, it forms a white powder. The dry pre- 
cipitate contains in 100 parts — ammonia 6*50; zinc-oxide 46*45; phos- 
phoric acid 33*68; water 13*37: it is probably a mixture of a double 
metaphosphate with a double phosphate containing ordinary phosphoric 
acid. (Bette.) 

I. Ammonio-htposulphitb op Zinc-oxide. — ^Aqueous hyposulphite 

of zinc-oxide supersaturated with ammonia and then mixed with absolute 

alcohol, deposits this salt in white needles. These crystals, when heated, 

rapidly evolve a large quantity of ammonia, yield a sublimate of sulphite 

of ammonia and a very small quantity of sulphate of ammonia, and leave 

a mixture of sulphide of zinc and sulphate of zinc-oxide. They are 

decomposed by water, with separation of floccnlent zinc-oxide. (Rammels* 

berg, Po^^. SQ, 62.) 

Cry$tallized, Rammelsberg. 

NH3 17*0 ..,. 16-16 

ZnO 40-2 .... 38*21 39*62 

820» 48-0 .... 45*63 

NH« + ZnO,8202 .... 105*2 Z 100*00 

K. Ammonio-hyposulphate op Zinc-oxide.— Warm aqueous am- 
monia saturated with hyposulphate of zinc- oxide, yields small crystals on 
cooling. These, when heated in a retort, yield free ammonia, a sublimate 
of sulphite and sulphate of ammonia, and leave a residue consisting of 
sulphate of zinc-oxide with a small quantity of sulphide of zinc. (Ram- 
melsberg, Fogg, 58, 297.) 

CryMtallized. Rammelsberg. 

2NH» ^ .340 .... 23-26 22-53 

ZnO 40*2 .... 27*50 27*50 

S'O* 720 .... 4924 

2NH3 + ZnO,S-0* 146*2 .... 10000 

L. QuADROBASic ZiNc-suLPHATE WITH Ammonia. — The flowers of 
zinc met with in commerce sometimes consist of this salt. It is precipi- 
tated when a boiling solution of zino-vitriol is supersaturated with 



38 ZINC. 

ammoniay and ib« boiling oontinaed till the liquid no longer smells of 

ammonia. (Schindler, Bepert, 81, 20.) 

Schindler. 

2NH» 340 .... 12-56 1200 

4ZnO 160-8 .... 5938 59*33 

SO» 40-0 .... 14-77 14-66 

4HO 360 .... 13-29 13-33 

2NH»+4ZuO,SO» + 4Aq 2708 .... 100-00 ZZ 9932 

The solution of quadrobasic or bibasic zinc-Bulpbate in ammonia yields 
small crystals on the addition of alcohol; but on dilution with water, it 
gives a precipitate in which the quantity of acid and ammonia is less in 
proportion as the dilution is greater. Aqueous monosulphate of zinc- 
oxide mixed with a quantity of ammonia just sufficient to re-dissolve the 
precipitate, is not rendered turbid by small quautities of water; but with 
larger quantities it forms pulverulent, and with still larger quantities, gela- 
tinous precipitates, containing oxide of zinc, sulphuric acid, and ammonia; 
when the quantity of water is still further increased, a heavy powder is 
thrown down consisting of nearly pure hydrated zinc-oxide. A solution 
of zinc-vitriol supersaturat^ed with ammonia and exposed for some time to 
the air, deposits quadrobasic sulphate of zinc-oxide, while sulphate of 
zinc-oxide and ammonia remains in solution. (Schindler, Jtfag, Pharm, 
3G, 57.) 

a is the precipitate formed by mixing zinc -vitriol with an insufficient 
quantity of ammonia, h. With a slight excess of ammonia. (If the 
addition of ammonia be discontinued as soon as the precipitate ceases to 
form, the double sulphate of zinc-oxide and ammonia remains in the 
solution.) c. The precipitate obtained by mixing zinc- vitriol with a 
quantity of ammonia sufficient to re-dissolve the precipitate and then 
diluting with water. (Bonnet.) [The amount of water is not stated.] 





a. 


h. 


c. 


NH» 


1-05 


4 u* ... 


2-42 


ZnO 


>... oa*2/ ... 


82-37 


81-65 


SO» 


16-68 


13-61 


15-93 




10000 


10000 


100-00 



M. MoNOBASTG Zinc-sulphate with Ammonia. — a. 5NH'-|- 
2(ZnO, SO'). 100 parts of anhydrous zinc- vitriol rapidly absorb 51*22 
parts (2^ At.) of ammonia, ^reat heat being evolved and the salt 
swelling up and ultimately crumbling to a white powder. The compound 
when heated to redness, gives off ammonia with ebullition, yielding a 
small sublimate of sulphite of ammonia, and a residue which is no longer 
soluble in water. It dissolves in water with partial separation of zinc- 
oxide. (H. Rose, Pogg, 20, 149.) 

h, 2NH'+ZnO, S0^ When ammoniacal gas is passed through a hot 
saturated solution of zinc-vitriol, till the precipitate is completely re-dis- 
solved., the compound c is deposited, on cooling, in flocculent granules. 
An additional quantity of the salt c is obtained by filtering the liquid 
from the precipitate and either evaporating it to dryness or keeping it 
warm. Ii, on the other hand, it be left to evaporate at ordinary tempera- 
tures, it yields crystals of 6. The latter are transparent while moist, but 
immediately become opaque when dried in the air, passing in fact, with- 
out change of form, from 2NH»-fZnO, S0'-f4Aq into 2NH»-hZnO, 
SCH+2Aq. When kept for awhUe at a temperature between 27"^ and 



SULPHATE OF ZINGH)XII)£ AND AMMONIA. 



39 



S6^ thej give off an additional atom of water and oramble to a white 
powder, coDsisting of 2NH»+ZnO, 80*-f Aq. The latter, if kept for 
awhile at 100^, gives off water and ammonia j bat to get rid of all the 
water it is necessary to fase the salt. If merely heated till it begins to 
melt, it leaves a gnmmy mass = NH' + ZnO,SO^+Aq; after longer 
fusion there remains NH'+ZnO,SO', constituting 79*13 parts out of 100 
parts of the white powder. This compound, when subjected to a con- 
tinually increasing heat, gives off all its ammonia, and leaves mono- 
sulphate of zinc-oxide. This last-mentioned salt constitutes 54*66 p. c. of 
the recently prepared crystals; 60 p. c. of the crystals after efflorescence 
in the air; and 66*07 p. c. of the white powder dried at 27^ If the 
heat be too suddenly applied, sulphite of ammonia sublimes and the 
residual zinc-sulphate contains excess of oxide. The crystals are soluble 



m water. 



NH' 

ZnoiSC 
HO 



At. 

2 
1 
1 



Bffiorewed above 27°. 

340 27*60 

80-2 6510 

90 7*30 



1 .... 123'2 

^/hreieed «/ ordinmy ten^tratune. 
At. 



10000 



NH> 2 

ZnO,80» 1 

HO 2 



34-0 25*72 

80*2 60-66 

18-0 13*62 



At. 
2 
1 

4 



Keemi ery$UUi, 



34*0 
80*2 
86-0 



22-63 
53-40 
23-97 



132-2 100-00 



150-2 .... 100-00 



e, NH'+ZnO, SO*. 1. Deposited in the preparation of h, in floccu- 
lent granules resembling starch. — 2. Obtained as a gummy mass by fusing 
b for a short time. In whichever way the compound is prepared, it 
contains 1 atom of water. When fused for a longer time, it gives off 
water, and when strongly heated, leaves 75-92 per cent of monosulphate 
of sinc> oxide. Both in the hydrated and in the fused state, it is decomposed 
by contact with water, the compound b together with sulphate of 
ammonia dissolving in the water, and sexbasic sulphate of zinc-oxide 
(p. 22) being separated. (Kane, Ann, Ckim. Fhy9, 72^ 304.) 



J>ehydtated. 

NH» 17*0 .... 17-49 

ZnO,S0« 80-2 .... 82-51 



Starch or gwm'Uke »alt, 

NH» 17-0 .... 16-01 

ZiiO,SO" 80-2 .... 75-52 

HO 9*0 .... 8-47 



• •■• 



97*2 



100-00 



106-2 



10000 



N. Sni.PHATE OF ZiNC-oxiDB AND Ahhomia.— ^t7»co-ammontc SuJtr 
phaU, Transparent, colourless, hard, bitter-tasting crj^stals, having pre- 
cisely the form of the doable sulphate of magnesia and ammonia. 
(Mitscherlich.) According to Tassaert {Ann, Chim, Phy9. 24, 100) they 
consist of ootohedral segments. 



NH» 


17-0 


8-49 
2008 
39-96 
31-47 

> ... *' 


Tassaert. 
804 


ZdO 


40-2 


19-74 


2S0» 


800 


39*90 


7HO 


63-0 


30-90 


FcO. accidental 




1-42 




• 




NH*0,80» + ZiiO,SO> + e 


lAq. ... 200*2 


... 10000 


.... lOOill) 



40 ZINC. 

0. Ammonio-iodide of Zinc. — a. 100 parts of zinc-iodide, exposed 
to a current of ammoniacal gas, absorb 26*923 per cent, (not quite 3 
atoms) of ammonia, becoming very hot, swelling up, and crumbling to a 
white, loosely-coherent powder. Cold water decomposes it, giving off 
ammonia and separating zinc-oxide free from iodine; but a small portion 
of zinc likewise dissolves. — b. The solution of zinc-iodide in aqneous 
ammonia^ when left to evaporate freely, yields anhydrous white crystals 
which have a strong lustre, are permanent in the air, and when heated 
in close vessels are resolved into ammonia which escapes as gas, and 
iodide of zinc which sublimes; cold water acts upon them just as upon 
salt a; they dissolve readily in acids. (Rammelsberg, Poffg. 48, 152.) 

Runmels* 
a. Rammelsberg. b. Crysiallured. berg. 

3NH»... 510 ... 24-38 ... 21-21 2NH»... 340 ... 1769 

Zo 32-2 ... 15-391 moo Zn 32-2 ... 1675 ... 16-66 

1 126-0 ... 60-23/ - '°^^ I 1260 ... 6556 

209-2 ... 10000 ... 10000 192-2 ... 10000 

P. Iodide of Zinc and Ammonium. — An aqneous mixture of iodide 
of zinc and hydriodate of ammonia, evaporated over oil of vitriol in a 
receiver contaming air, yields extremely deliquescent crystals. (Rammels- 
berg, Popsr, 43, 665.) 

CryttaUised, Rammelsberg. 

NH< 180 ... 5-96 

Zn 32-2 ... 10-65 10-269 

21 2520 ... 83-39 80644 

NH^I,ZnI 302-2 ... 10000 

Q. Ammonio-iodate of Zinc-oxide. — Separates from a solution of 

zinc-iodate in ammonia, in rhombic crystals by spontaneous evaporation, 

and as a white powder on the addition of alcohol. The crystals, when 

exposed to the air, effloresce rapidly from loss of ammonia. When heated, 

they melt and leave oxide of zinc. They are decomposed by water. 

(Riunmelsberg, Pogg. 43, Q^5,) 

CryitiUlized. Rammelsberg. 

4NH» 68-0 ... 9-90 10-64 

3ZnO 120-6 ... 17*57 18-03 

310» 4980 ... 72-53 71-33 

4NH» + 3(ZnO,IO») 686*6 ... 10000 ~. 100-00 

R. Ammonio-bromide of Zinc. — A concentrated aqueous solution of 
zinc-bromide, supersaturated with ammonia and evaporated, yields colour* 
less octohedrons, which fuse and give off all their ammonia when heated; 
and when digested with water, especially with the aid of heat, are com- 
pletely resolved into precipitated oxide of zinc, and a solution of hydro« 
Dromate of ammonia free from zinc. (Rammelsberg, Pogg. 55, 240.) 



Zn .. 
Br .. 



Cryttalfized, 


Rammelsberg. 


170 ... 13-32 


12-98 


32*2 .... 25-24 


25-82 


78-4 ... 61-44 


59-87 



NH»,ZnBr 1276 ... 10000 9867 

S. Ammonio-bromatb of Zinc-oxide. — When ammonia is added to an 
aqueous solution of zino-bromate till the precipitate first formed is re-dis- 



AMMONIO-CHLORIDE OF ZINC. 41 

solved, and the liquid eyaporaied [best nnder a bell-jar with hydrate of 
potash and quick-lime], small prismatic crystals are obtained. These 
crystals when heated, are decomposed with a hissing noise and a back- 
ward and forward motion, and give off bromine. With water they are 
converted into oxide of zinc and bromate of ammonia which dissolves. 
When exposed to the air, they attract moisture and turn yellow, evolving 
bromine and afterwards giving up bromide of zinc to the water. (Ram* 
melsbergy Fogg, 52, 90.) 

Crytiallized. Rammelsberg. 

NH' 170 ... 8-39 8-52 

ZnO 40-2 ... 19-84 19*41 

BrO* 118-4 ... 58-44 

3HO 27-0 ... 13-33 

NH» + ZnO,BrO» + 3Aq. ... 202*6 ... 10000 

T. Ammonio-chlortde op Zinc. — a. 2NH',ZnCL — Formed by 
passine ammoniacal gas through a hot concentrated solution of zinc- 
chloride till the precipitate is re-dissolved — filtering quickly, in case any 
flocculent matter should remain undissolved — and leaving the solution to 
cool. The compound a then separates. The mother-liquor, when evapo- 
rated, yields crystals of the compound h. — a appears m small laminae, 
having a pearly lustre and feeling like mica. ■ At 149° it gives off all its 
water and half its ammonia, and leaves 77' 22 per cent, of a white powder, 
consisting of NH*,ZnCl. When more strongly heated, it leaves NH', 
2Zn.Cl. (Kane, Ann. Chim. Phys. 72, 290.) 

Cryitaliized. Kane. 

2NH» 34-0 ... 30-74 

Zn 32-2 ... 2911 

CI 85-4 ... 3201 3114 

HO 90 ... 8-14 

2NH»+ZiiCl-*-Aq. 110-6 ... 100*00 ^ NH»,ZnCl + NH»,HO. 

h, NH*,ZnCl. — For the preparation, vid, a. — Square prisms having 
a glassy lustre. The compound fuses when heated, giving off its water 
and half its ammonia, and forming a transparent liquid composed of 
NH',2ZnCl, and amounting to 85*64 per cent, of the original substance. 
(Kane.) 

Crystallized. Kane. 

2NH» 340 ... 19*08 

2Zn 64*4 ... 3614 3561 

2C1 70-8 ... 39*73 3947 

HO 90 ... 505 

2NH» + 2ZnCl + Aq 178*2 ... 100*00 

c. NH',2ZnCl. — When a or & is fused, this compound remains in the 
form of a clear, colourless or yellowish liouid which, on cooling, solidifies 
into an amber-yellow, gummy, very slightly crystalline mass. It boils at 
a heat near redness and sublimes undecomposed in amber-coloured drops. 
W^hen heated with lime, it evolves a large quantity of ammonia. When 
treated with water, it is resolved into the compound b, which dissolves, 
and oxychloride of zinc, ZnC],6ZuO -|- 6Aq (p. 82), which rAnains undis- 
solved. (Kane.) According to Grouvelle, chloricte of zinc absorbs am- 
moniacal gas; according to Perzoz, the quantity absorbed is half an atom, 
and the imorption does not take place without the aid of heat 



42 ZINC, 

NH» 17*0 1M7 

2ZnCl 135-2 8883 

NH',2ZnCl 152-2 10000 

U. Chloride of Zn«c and Ammonium. — A Bolution of 1 part of zinc- 
oxide in strong hydrochloric acid mixed with I part of sal-ammoniac and 
eTaporated — the acid, as it escapes, being replaced — ^yields on cooling, 
transparent and colourless rectangular prisms, truncated at the lateml 
edges and the corners, and having a sharp metallic taste. They are per- 
manent in dry air, but deliquesce in moist air, and dissolve without decom- 
position in water. (Schitidler, Mag Pharm. 30, 37.) When heated, they 
are resolved into sal-ammoniac which volatilizes, and chloride of zinc which 
remains behind. They dissolve into ■} pt. of cold water, produciug a 
great fall of temperature and in 0'28 pt. boiling water. (Golfier — 
Basseyre, Ann, Chim, Phyt, 70, 344.) 

CryttaUiMed. Sebindler. 

NH*C1 53-4 ... 4108 41*20 

ZnCl 67-6 ... 5200 5202 

HO 90 ... 6-92 6-71 



NH<Cl,Zna + Aq 130-0 ... 10000 100-00 

Oxide of zinc dissolves in aqueous Bal-ammoniao, (Th^nard, iSc^. «/*. 
10, 428.) A solution of hydrated ziuo-oxide in gently-warmed oal^ 
ammoniac yields the above-mentioned crystals on evaporation j but, if it 
be boiled, the ammonia escapes, and basic hydrochlorate of zinc-oxide 
a (page 31) is produced, from which the compound b is precipitated on 
cooling. (Sebindler.) 

When chloride of zinc is precipitated by an insufficient quantity of 
ammonia, a precipitate is formed, containing oxide of zinc79'8(jj chloride 
of zinc 14*80; sal-ammoniac 2*37; a slight excess of ammonia produces a 
gelatinous precipitate which exhibits an alkaline reaction, even after long 
washing, and contains 2'42 per cent, of ammonia and 11*16 chlorine; the 
liquid filtered from it yields crystals of the double chloride of zinc and 
ammonium. (Bonnet, Ann. Fharm, 9, 170.) 

IF By mixing solutions of 1 pt. sal-ammoniac and 2 pts. chloride of zinc, 
Hautz obtained a salt which separated in crystals belonging to the 
oblique prismatic system. The crystals were very soluble in water and 
showed a tendency to deliquesce wnen exposed to the air. 

CrytiaUixtd, Hants. 

NH< 180 ... 7-95 8-00 

2Zn 66-4 .... 2917 29*05 

3C1 106*2 ... 46*95 46*46 

4HO 360 ... 15*93 16*26 

NH*Cl,2ZnCl + 4Aq. 226*6 ... 10000 ~. 99*77 

{Ann, Pharm, 60, 287.) IT 

Zinc and Potassium, 

A. Alloy op Zino and Potasbthm.— -Combination between these 
two metals takes place at high temperatures only. — The alloy is a brittle, 
granular mass, which fuses at a red heat. — It oxides in the air, and 



SULPHATE OF ZINC-OXIDB AND POTASH. 43 

decompose* water rapidlj^ eepeoiaUj when acids are present. (Gfaj* 
LoBsaCy and Thenard.) 

B. Zinc-oxide with Potash. — Zinc dissolves in aqueous solution of 
potash very slowly aud with evolution of hydrogen (Bischof, Kastn. Arch. 
1, 193); more quickly when in contact with platinum ; most quickly in 
contact with iron. (Runge, Po^. 16, 129.) The ignited oxide dissolves 
with difficulty; the hydrate easily and abundantly. — The concentrated 
solution^ when covered with a layer of alcohol, deposits small shining 
crystals, containing 1 At. zinc-oxide with 1 At. potash. They dissolve 
readily in water, and the solution, when boiled, deposits a white powder 
containing 2 At. zinc-oxide to 1 At. potash. (Laux, An7i, Pharm, 9, 183.) 
By the addition of a small quantity of alcohol, Fr6my (Compt. rend. 
15, 1106) obtained long needles containing 2 At. zinc-oxide with 1 At. 
potash; these, when treated with water, were immediately decomposed, 
yielding anhydrous zinc-oxide and aqueous solution of potash. — The 
solution of zinc-oxide in aqueous potash leaves on evaporation a white 
shining mass which becomes moist oy exposure to the air. (Berzelius.)— * 
2 parts of hydrated zinc-oxide dissolve in 5 parts of potash-ley of 1 '3 
specific gravity. When the solution is evaporated to dryness and the 
residue fused, an enamel-like mass is formed, from which water extracts 
the potash; the solution mixed with eight times its volume of alcohol 
deposits nearly the whole of the zinc-oxide. (Bonnet.) — The solution of 
zinc-oxide in caustic potash is rendered turbid only by a very large 
quantity of water. 

When a solution of zinc-vitriol is mixed with a quantity of potash 
sufiScient to re-dissolve the precipitate, and then exposed to the air for 
some time^ a precipitate is formed containing zinc-oxide, potash, and 
carbonic acid, out no sulphuric acid. The mixture yields no deposit, 
when boiled out of contact of air; but when it is boiled in an open vessel, 
or if it has been exposed to the air before boiling, it yields a powder 
which becomes very heavy when dry and consists of pure hydrated oxide 
of zinc. If the potash contains silica, silicate of zinc-oxide and potash is 
formed on boiling. The precipitate which Vauquelin & Buchner 
(Repert. 14, 381) obtained by boiling a solution of potosh saturated with 
zinc-oxide, and which, according to their statement, consists of zinc-oxide 
mixed with a small quantity of potash, is likewise regarded by Schindler 
as silicate of zinc-oxide and potash. Water added to the mixture throws 
down a large quantity of zinc-oxide containing potash, sulphuric acid, 
and water; a larger quantity of water precipitates the pure hydrated 
oxide. (Schindler.) — Zinc-oxide boiled with aqueous carbonate of potash 
extracts potash from that compound, and afterwards exhibits an alkaline 
reaction on turmeric paper; the potash may be removed from it by long 
washing with water. (Wackenroder.) 

C. Carbonate op Zinc-oxidb and Potash. — Zinco-potasnc Car- 
bonate. — A zinc-salt precipitated by excess of carbonate of potash at 
ordinary temperatures, yields a stiff, gelatinous precipitate, which cakes 
together in drying, and consists of a mixture of -^carbonate of zinc-oxide 
(p. 12) and double carbonate of zinc-oxide and potash. Gives off all its 
carbonic acid when ignited. (Schindler, Maff. Pkarm. 36, 5Q.) 

D. SnLPHATB OF ZiNC-oxTDB AND PoTASiT. — Zitico-potatsic Sulphate, 
^-Crystallizes in the same form as sulphate of magnesia and ammonia. 
(Mitscherlioh.) Fig. 84;i^ : w=102^ 20'; w' : tt=108^ 40'. (Tesohemachor, 



44 ZINC. 

Kastn, Arch. IS, 197.) Sp. gr. 2.153. (Kapp.) The ciystals hare an 
acid reaction. In vacuo, they give off 5 atoms of water at 25*5^, but the 
sixth thej retain till heated to 121^ (Graham.) Soluble in 5 parts of 
cold water. (Bucholz. Junr. N. Tr. 9, 2, 26.) 

Cryttallized. Bnchob. 

KO 47-2 .... 21-32 18-2 

ZnO 40-2 .... 18-16 21-4 

2SO» 80-0 .... 36-13 36*2 

6HO 540 .... 24-39 245 

KO, 80» + ZnO, 80» + 6 Aq. 2214 .... 10000 ZZ 100-3 

E. Iodide of Zinc and Potassium. — Zinco-potamc Iodide. — A 
solution of iodide of zinc and iodide of potassium evaporated over oil 
of vitriol under a receiver containing air, yields very deliquescent crystals. 
(Rammelsbergy Pogg. 43^ 665.) 



K 

2Zn 

31 


39-2 

64-4 

3780 


.... 8-14 . 
.... 13-37 
.... 78-49 


Rammelsbeii;. 
12-95 


KI 

2ZnI 


Or: 
... 165-2 .... 34-4 
... 316-4 .... 65-6 


KI,2Znl.... 


481-6 


.... 100-00 


••••••• 




481-6 .... 100-0 



F. CnLORiDE OF Zinc and Potassium. — Zinoo-potasdc ChUyride. — 
The preparation, crystalline form, and other properties of this compound 
are precisely similar to those of the chloride of zinc and ammonium; but 
it deliquesces more rapidly. (Schindler.) 

G. Fluoride of Zinc and Potassium. — Zinco-potamc Fluoride, — 
KF^ZnF. — Colourless, crystalline granules, soluble in water. (Berzolius.) 

On the properties of crystals obtained by supersaturating nitrate of zinc with 
iodide of potassium, and oontdning nitric add, vid. Anthon, Reptrt, 51, 115. 



Zinc and Sodium. 

A. Alloy of Zinc and Sodium. — Four Yolumes of zinc-filings unite 
with 1 Tolume of sodium at a dull red heat, and form a bluish-grey, 
brittle alloy which has a finely laminar texture, oxidates slowly in the 
air, and effervesces slightly with water, but strongly with aqueous acids. 
(6ay-Lussac and Thenard.) 

B. ZiNC-oxiDE wirn Soda. — Hydrated zinc-oxide dissolves readily in 
aqueous solution of soda; metallic zinc only when heat is applied; it then 
dissolves with evolution of hydrogen. (Lassonne.) The solution, when 
exposed to the air, deposits small shining crystals of hydrated obasic 
zinc-carbonate. (Wbhler.) Zinc-oxide boiled with solution of carbonate 
of soda extracts from it only a trace of soda; if sulphate of soda is mixed 
with the solution, the zinc-oxide extracts from it both soda and sulphuric 
acid, which it retains with great obstinacy. (Wackenroder.) 

C. Carbonate of Zinc-oxide and Soda. — Zincosodic Carbonate. — 
Zinc dissolves slowly in aqueous carbonate of soda, with, evolution of 
hydrogen. The solution, set aside for a few days, deposits small, colour- 
less, strongly lustrous, hard, regular tetrahedrons and octahedrons, having 
their edges and solid angles truncated. They become opaque when 



ZINC AND BARIUM. 45 

heated, and tarn yellow on ignition; and if afterwards treated with water, 
they yield a solution of carbonate of soda and a residue of pure oxide of 
zinc. (Wbhler, Pogg. 28, 616.) Oxide of zinc does not disi*olve in car- 
bonate of soda fused before the blowpipe. 

B. Zinc-oxide dissolves in Borax and in Microcotmic salt, yielding a 
clear glass which becomes milk-white on gentle flaming, and if the zinc- 
oxide is in excess, becomes enamel-white on cooling. 

E. Sulphate of Zinc-oxide and Soda. — Zincosodte Sulphate,^- 
Separates from a solution of zinc-vitriol and bisulphate of soda, when 
evaporated in vacuo over oil of vitriol. (Graham.) According to 
Oranam, monosnlphate of soda and zinc-vitriol, mixed in any propor- 
tions whatever, do not yield this double salt, but each salt crystallizes 
out by itself. Karsten, on the other hand (JSchrift d. Berl. Akad, 1841), 
obtained crystals of the double salt, both by mixing Glauber's salt with a 
saturated solution of zinc- vitriol, and setting the mixture aside for a few 
days, and likewise by dissolving zinc-vitriol at ordinary temperatures in 
a saturated solution of Glauber's salt, and leaving the mixture to 
evaporate either spontaneously or with the aid of heat; it was only 
when the mixture was strongly heated and then suddenly cooled, that 
the two salts crystallized out separately. Karsten likewise obtained the 
double salt with common salt and zinc-vitriol. 

The dehydrated salt melts without decomposition at an incipient red- 
heat, and on cooling, solidifies in a white, opaque mass. The salt crys- 
tallizes in tables contains 4 atoms of water; it deliquesces only in moist 
air, and when dissolved in water, separates into the two simple salts. 
(Graham, Phil. Mag. J. 18, 417.) 

F. Iodide op Zing and Sodium. — Zinco-sodtG Iodide. — Preparation 
and properties, similar to those of the potassium-salt. (Rammelsberg.) 

Crystallized. Rammelsberg. 

N» 23-2 .... 6-94 6-95 

Zn 32-2 .... 9*62 9*41 

21 2520 .... 75-36 7485 

3HO 27-0 .... 8-08 

NaI,ZnI + 3Aq 334*4 .... 10000 

O. Chloride of Zinc and Sodium. — Zinco-iodic Chloride. — An 
aqueous solution of common salt and zinc-chloride quickly evaporated 
yields six-sided laminse, having a sharp taste, and easily soluble. If the 
solution be slowly evaporated, the chloride of sodium crystallizes out 
alone. (Schindler, Mag. Pharm, 36, 48.) 



Zinc and Barium. 

Iodide of Zinc and Barium. — Zineo^'t^yiic Iodide. — Preparation 
and properties similar to those of the potassium-salt. 

Crystallized. Rammelsbei^. 

Ba 68-6 .... 13'42 11-71 

2Zn 64-4 .... 12*60 12*80 

31 3780 .... 73*98 

B«I»2Znl 511*0 .... 100*00 



4A ZINC. 

Barjta, fitrontia,' and lime diBSolved in water, and mixed with the 
compound of zinc-oxide and ammonia, deprive that compound of part of 
its zinc-oxide, and are precipitated in combination with that oxide. 
(BerzeliuB.) 

Zinc amb Magnesium. 

Sttlphate op Ztnc -oxide and Magnesia. — Zine<Hnagnesic Sulphate. 
-^Sulphate of magnesia dissolves in a cold saturated solution of zinc- 
yitriol forming a clear li<^uid at first; but after awhile, the double salt is 
deposited. (Karsten.) 

Zinc and Aluminum. 

A. Aluminatb OF Zinc-oxide. — a. Gahniie. — Regular octohedrons; 
8p.gr. 4'23. Harder than quartz; translucent, green; yields a pale 
bluish-green powder. Does not fuse before the blowpipe; bakes together 
with carbonate of soda without dissolving in it, and forms a dark- 
coloured slag, which, when finely pulverized, forms a deposit of zinc- oxide 
upon the charcoal; dissolves sparingly and with great difficulty in borax 
or in microcosmic salt; dissolves in a mixture of borax and carbonate 
of soda, forming a clear glass coloured by iron, (Berzelius.) Insoluble 
in aqueous acids and alkalis. 



Abich. 



Oaknite. 

MgO 

ZnO 40-2 .... 43-9 

FeO 

Al«0» 51-4 .... 56-1 

Si02 



Fkhlnn. 


Aaierici 


5-25 


2-22 


3002 


34-80 


5-85 


4-55 


5514 


5709 


3-84 


1-22 


10010 


99-88 



ZnO,Al*0» 91-6 .... 1000 

Fart of the ZnO is replaced by MgO and FeO. 

6. Hydrate of alumina abstracts the zinc-oxide from the aqueous 
solution of the compound of zincoxide and ammonia; aluminate of zinc- 
oxide is likewise precipitated on mixing the compound of zinc-oxide and 
ammonia with a saturated solution of hydrate of alumina in potash. 
This compound is soluble in potash. (Berzelius.) The compound of zinc- 
oxide and potash likewise forms, with aluminate of potash, a precipitate 
soluble in excess of potash. (Sander, Ann, Fharm. 9, 181.) 

B. Sulphate OF Alumina and Zlng-oxidb« — Zin<Hdum=zZnO,SO^+ 
Al»0',3SO» + 24Aq. (Kane.) 

C. Fluoride op Aluminum and Zinc. — ZnP,Al'F*. — Formed by 
evaporating the aqueous solution of hydrofluate of zinc-oxide and hydro- 
fluate of alumina. Long, colourless needles, slowly but completely 
soluble in water. Ammonia added to the solution throws down aluminate 
of zinc-oxide. (Berzelius.) 

ZiNO AND SiLTCIUM. 

A. Silicate of Zinc-oxide. — Zinc-Glance or SUiceotu Calamine 
occurs in transparent and colourless crystals belonging to the right 



ZINC AND MOLYBDENUM. 47 

prismatic system. Right rhombio prisms, haying the obtuse (rarely also 
the acute) lateral edges replaced by pUnes, with two bevelling surfaces 
resting sometinies on the two acute, sometimes on the two obtuse lateral 
edges. Cleavage parallel to u and p, Sp. gr. 3 '38. Harder than felspar. 
— 'Decrepitates slightly when heated, losing water and becoming opaque; 
does not fuse before the blowpipe, bat swells up when strongly ignited; 
iatumesces slightly with carbonate of soda but does not dissolve in it, and 
gives, though not readily, a deposit of sine-oxide. In borax or micro- 
cosm io salt^ it fuses to a transparent glass, which, however, becomes 
turbid on cooling. With nitrate of cobalt it assumes a green colour 
when gently heated, light>blae on the edges when more strongly ignited. 
^Berzeiius.) Dissolves readily in acids, with separation of a siliceous 
jelly; dissolves for the most part in caustic potash. 

Berzelius. Berthier. Smithson. 
Limlmif . Bre!igaa. iletibuiyt. 

2ZnO 80-4 ..„ 66'78 .... 66-37 .... 64«5 .... 68S 

SiO« 310 .... 25-75 .... 26*23 .... 25-5 .... 250 

HO 90 .... 7-47 .... 7-40 .... 100 .... 4'4 

2Z&0,SiO>+Aq. 1204 .... 10000 .... 10000 .... 1000 .... 977 

The same compound occnra in the anhydrous state but impure, as 
WiUiamfke or Hebetine, 

B. Hydratsd Fluoride of Siltgium and Zino, or HrDROFLirAtB 
OF Silica aiyd Zino-oxidb. — A solution of sine-oxide in hydrofluosilieic 
acid yields, when evaporated at a high temperature, three and six<sided, 
transparent^ colourless prisms, permanent in the air^ and very easily 
soluble in water; ZnF,SiP+7Aq. (Berselius.) 

C. Silicate of Zing-oxide and Potash. — Separates in white flakes 
when zinc in contact with iron is dissolved in potash-ley containing silica. 
The flakes contain water; they dissolve in excess of caustic potash, and 
likewise, with separation of a jelly, in acids. (Schindier.) 

Zinc and Tungsten. 

A. Tungstate of Zinc-oxide. — ^White powder, insoluble in water. 

B. Sulphotungstate of Zinc. — ZnS, WS*. The mixture of an 
aqueous zinc-salt with sulphotungstate of potassium gives after 24 hours, 
a pale yellow^ pulverulent precipitate. (Berzelius.) 

Zinc and Molybdenum. 

A. MoLTEDATfi OF ZiNO-oXiDE. — Formed by precipitating a zinc- 
■tit with molybdate of ammonia. Yellowish-white powder, sparingly 
soluble in water, more easily soluble in acids, and containing, according 
to Brandos, 36 25 zinc-oxide and 68*75 molybdic acid. 

B. Sulpbomoltbdatb of Zinc. — Dark brown precipitate, insoluble 
in water. (Berseiius.) 

C. Persulfhoholybdate of Zinc. — Red precipitate. (Beneiins.) 



48 ZINC. 

D and E. Moltbdate of Zinc-oxidb and Ammonia, and Moltb- 
DATR OP Zinc-oxidb and Potash. — Both these double salts are soluble 
in water. (Berzelios.) 

Zinc and Vanadium. 



Vanadiate op Zinc-oxidb.— «. MonovanadiaU.'^'By double decom- 
position. White precipitate, insoluble in water, eyen at a boiling heat. 
h. Bivanadiate. — Transparent, orange-yellow crystals, soluble in water. 
(Berzelius.) 

Zinc and Chromium. 



Chromate op Zinc-oxide. — a. Bichromate, — The yellow precipitate 
which monochromate of potash produces in a solution of zinc-vitriol. 
^Thomson, Phil. Mag, Ann. 3, 81.) When the chromate of potash is 
aropt into a boiling solution of zinc- vitriol, the precipitate formed has a 
peculiarly fine yellow colour. (Bensch.) The supernatant liquid remains 
yellow eyen wnen the zinc-salt is in excess. [It probably contains bi- 
chromate of potash.] Zinc- salts are not precipitated by bichromate of 
potash. (Wohler.) 

6. Monochromate. — A solution of zinc-carbonate in aqueous chromic 
acid yields transparent, topaz-yellow crystals, haying the form of zinc- 
yitriol and a specific gravity of 2*096 at 15^ The crystals are easily 
soluble in water, and when heated, dissolve in their water of crystalliza- 
tion; the dehydrated salt is strongly heated by contact with water. 
(Kopp, Ann, Fharm, 42, 98.) 

Kopp. 

ZnO,CrO» 92-2 .... 59-41 57-8 

7HO 1.. 630 .... 40-59 42*2 

ZnO,CrO»+7Aq.... 155*2 .... lOO'OO ZZ 100*0 

% By subsequent examination, Kopp has discovered that the crystals 
which he originally took for pure chromate of zinc-oxide, really consisted 
of ordinary zinc-sulphate containing small quantities of zinc-chromate 
intimately bound up with them : the crystals when dissolved in water 
gave the reactions of chromic acid, but contained only 3*5 per cent, of 
that acid, instead of 33*6 as required by the formula, ZnO, CrO'-|-7Aq. 
The formation of the zinc-sulphate is due to the presence of sulphuric 
acid in the chromic acid used in the preparation. (Ann. Pharm, 57, 
386.) IT 

B. Chromatb of Zinc-oxidb and Potash. — Zinco-potassic Chromate. 
If the yellow flocculent precipitate obtained by mixing zinc-vitriol with 
monochromate of potash be left immersed in the liquid for 24 hours, it 
changes to an orange-yellow powder, which is a compound of chromate of 
potasn with chromate of zinc-oxide. It loses by ignition 15 per cent, of 
oxygen and water, and leaves a dark brown powder from which water 
extracts a quantity of monochromate of potash amounting to 21 per cent, 
of the double salt, and leaves violet-brown Chromiie of Zinc-oxidey which 
dissolves in oil of vitriol, forming a dark-green solution. The double 
salt is slightly soluble in cold water and imparts a yellow colour to large 
quantities of it; in boiling water it forms a deep yellow solution, with 
separation of a lighter-coloured salt, probably basic. (Wohler, JSerzelius 
Lehrh. 4, 487.) 



SULPHARSBNITE OF ZINC. 49 

Zinc and Uranium. 

Uranatb op Zinc-oxide. — 1. By precipitatiug zinco-uranic acetate 
with baryta-water. — 2. When uranic nitrate is precipitated by zinc, the 
zinc becomes covered with a solid yellow film of uranate of zinc-oxide, 
which prevents farther combination. (Wertheim, J. pr. Chem. 29, 227.) 

Zinc and Manganese. 
Permanganate of Zinc-oxide.— Deliquescent. (Mitscherlich.) 

Zinc and Arsenic. 



A. Arsenide op Zinc. — a. When 75*2 parts (1 At.) of arsenic- 
powder is brought in contact with 128*8 parts (4 At.) of zinc fused but 
not red-hot, combination takes place, the whole mass glowing vividly 
with a dark red light, and some of the arsenic volatilizing. (A. Vogel.) 
h. With 64-2 parts (2 At.) zinc and 75*2 parts (1 At.) arsenic similarly 
treated, the ignition is less vivid, because the resulting compound is less 
fusible and solidifies more quickly. This compound, when treated witb 
hydrochloric acid, gives off pure arseniuretted hydrogen, without any 
admixture of free hydrogen. (A. Vogel, /. pr. Chem. 6, 345.) 100 parts 
of zinc-turnings heated with 100 parts of arsenic-powder combine without 
ignition and yield 172 parts of a very brittle idloy. (Gehlon.) Equal 
parts of granulated zinc and pulverized arsenic heated in an earthen 
retort at a gradually increasing temperature, yield a well -fused, grey, 
brittle alloy, having a fine-grained fracture; this alloy, when dissolved in 
dilute sulphuric acid, evolves pure arseniuretted hydrogeu gas, and leaves 
a grey metallic powder which contains excess of arsenic, gives off that 
excess when heated, and is thereby rendered soluble in acids. (Soubeiran.) 
Arsenide of zinc is likewise obtained by heating zinc with arsenious acid, 
(Bergman.) With 2 parts of zinc-cuttings and 1 part of arsenious acid, 
the reaction takes place with combustion and explosion. (Gehlen.) 

B. Arseniate op Zinc-oxide or Zinc- arseni ate. — Tris-arseniate. 
When di-arseniate of ammonia, potash, or soda is mixed ^ith a zinc -salt, 
the liquid turns sour, and tris-arseniate of zinc-oxide is precipitated. 
(Mitscnerlich.) The precipitate formed by arsenic acid in a solution of 
zinc-acetate is either the same salt, or a di-arseniate. White powder, 
insoluble in water, but soluble in arsenic and nitric acid. Hydrogen gas 
passed over the ignited salt, decomposes it, according to Soubeiran, into 
water, arsenic, and zinc-oxide, the latter remaining behind. 

b. Acid Sail. Formed by dissolving zinc, the oxide, or the salt a in 
arsenic acid. When metallic zinc is used, arseniuretted hydrogen is given 
off, and solid arsenide of hydrogen separates in the form of a brown powder. 
The acid solution yields cubes on evaporation. (Berzelius.) When com- 
pletely saturated with zinc, it solidifies to a transparent jelly. (Fischer, 
Poffst' 9, 261.) 

G. Htposulpbarsenitb op Zinc. — ^Yellowish red. (Berzelius.) 

D. SuLPHARSENiTE OP ZiNC. — Hydrosulphato of soda saturated with 
arsenious sulphide, forms, with neutral zinc-salts, a bulky, lemon-yellow 

VOL, V. E 



50 ZINC. 

precipitate which hecomes orange-yellow on drying. This, when gently 
heated, gives off part of the arsenious sulphide, and leaves a hard, yellow, 
agglomerated compound of zino-snlphide with a small quantity of arsenious 
sulphidej the latter is completely driven off at the melting point of glass.' 
(Berzelius, Fogg, 7, 145.) 



E. Sttlpharsekiatb op Zinc. — a. Terbasic salt. — dZnS,AsS^ — By 
precipitating a zinc-salt with trisulpharseniate of sodium. Pale yellow 
flakes, which, when dry, yield an orange -yeUow powder. — 6. Bihasic. 
2ZnS, AsS^ By precipitating with disulpharseniate of sodium. Forms 
somewhat brighter yellow flakes, but exhibits the same colour as a t^hen 
dry. (Berzelius.) — c. Monobasic. — When zinc-oxide and arsenic acid are 
dissolved together, even in a very large excess of hydrochloric or sulphuric 
acid, sulphuretted hydrogen precipitates the whole^of the zinc [provided 
the quantity of arsenic acid is sufllcientj in the form of yellow ZnS, AsS^ 
But if the arsenic acid be previously reduced to the state of arsenious acid 
by the action of sulphurous acid, sulphuretted hydrogen precipitates only 
tersulphide of arsenic, and leaves all the zinc in solution. (Wohler, 
Jakrefh. 21, 2, 150.) 

P. Arseniate op Zinc-oxide with Ammonia. — Formed by mixing 
hydrochlorate of zinc-oxide with a quantity of sal-ammoniac sufficient to 
prevent precipitation by ammonia, and then digesting the solution with a 
mixture of ammonia and arseniate of potash. The precipitate, which is 
flocculent at first and afterwards becomes crystalline, forms, after pressure 
between paper and drying, a white powder, soluble in acids, ammonia, 
and potash, but not in water. At 1 00^ it gives off the greater part of its 
water with a portion of ammonia, and on ignition leaves a residue 
amounting to 84*33 per cent., and consisting of 43'57 zinc-oxide with 
40*76 arsenious acid. (Bette, Ann. Pharm, 15, 141.) 



3ZnO 

AbO* 

3HO 







Bette. 


170 


..>• b'UO ...a 


6*97 


120-6 


• ••• 40 Iv ■••• 


43-57 


1150 


••.. 41*19 ...• 


40*76 


270 


.... "*00 ••.. 


9-70 



NH» + 3ZnO,ABO* + 3Aq. 279*6 .... 10000 , 10000 



Zinc and Antimony. 

A. Antimonibe oJ" Zinc— These two metals fuse together with 
facility— and, according to Gehlen and A. Vogel, without emission of 
light — and form a hard, brittle, steel-coloured alloy, whose density is less 
than the medium density of its elements. (Gellert.) 

B. Antimoniate op Zinc-oxide. — The precipitate formed in a 
solution of zinc- vitriol by a small quantity of antimoniate of potash dis- 
appears again, and does not become permanent till a larger quantity of 
autinioniate of potash is added; white crystalline grains are then depo- 
sited, in the course of a few hours, on the sides of the vessel. The salt 
when heated, gives off all its water and turns yellow, but without any 
appearance of luminosity. It does not fuse before the blowpipe on char- 
coal and can only be reduced by addition of an alkali; it is very slightly 
soluble in water. (Berzelius.) 



OTHER COMPOUNDS OP ZINC. 61 

C. SuLPHANTiMONiATE OP ZiNC— 3ZnS,SbS^ Zinc-vitpiol dropt 
into excess of aqueous snlpliantimoniate of sodium, forms a deep orange- 
yellow^ precipitate, which dissolves in the liquid on boiling, and passes 
through the filter during washing. If the zinc-sulphate be added in 
excess and the liquid boiled for a short time, a deep orange-yellow preci- 
pitate is formed, which dries up to a brown-red mass haying a shining 
fracture. This substance^ when ignited in a retort, yields sulphurous acid 
and sulphur, and leaves a half-fused residue amounting to 82-9 per cent. 
It dissolves in boiling hydrochloric acid. In caustic potash it dissolves 
with separation of ziao-sulphide, and forms a yellow solution, from which 
acids precipitate pentasulphide of antimony, with slight evolution of 
sulphuretted hydrogen. (Rammelsberg, Pagg, 52, 223.) 

Rammelflber;. 

4Zn 128-8 .... 32-71 30'85 

8b 1290 .... 3276 30-81 

8S 1280 .... 32-50 33-17 

O 80 .... 2-03 

3ZnS,SbS» + ZnO 893-8 .... 100-00 

Zinc akd Tellttrxttm. 

A. Telluride or Zinc. — These metals when heated unite with 
great evolution of heat, and form a grey, porous, difficultly soluble alloy, 
having a metallic lustre and crystalline fracture, insoluble in strong 
sulphuric or hydrochloric acid. (Berzelius, Lthrh, 3, 384.) 

B. Tellurite of Zinc-oxibe.— By double decomposition. White 
flakes. (Berzelius.) 

C. SuLPHOTBLLVRiTE OP ZiNC. — dZnS,TeS'.— By double decomposi- 
tion. The precipitate, which is light-yellow at first, gradually turns 
brown. (Berzelius.) 

ZiNO AND Bismuth. 

Alloy of Zinc and JSismuih? — The two metals will not unite by 
fusion. (Cramer.) On melting them together in equal parts, two layers 
are formed, the upper consisting of zinc, the lower of bismuth containinc^ 
a small quantity of zinc, and therefore of a lighter red; finer-grained and 
more brittle than pure bismuth, but expanding with equal force as it 
solidifies. (Marx, JSchw, 58, 465.) By fusing together 16*12 pts. (6 At.) 
zinc and 17*73 pts. (1 At.) bismuth, an upper layer is formed, consisting 
of zinc and amounting to 13 '40 parts, and a lower layer, amounting to 
19*40 parts and consisting of bismuth, which, where it borders on the 
zinc, is somewhat more laminar, in consequence of admixture of zinc; 
but no chemical compound is obtained. (Foumet, Ann, Chim, FhyB, 24, 
247.) 

Other Compounds op Zinc. 

With Tin, Lead, Iron, Cobalt, Nickel, Copper, Mercury, Silver, Gold, 
Platinum, and Palladium. Very small quantities of tin, lead, iron, 
copper, or mercury, diminish the solidity of zinc; a very small quantity of 
iron or copper accelerates its solution in acids; a very small quantity of 
lead or mercury, especially the latter, retards the i^olution. (Karsteo, 
J, pr. Chem. 16, 380.) B 2 



52 



Chaptbr XXIX. 



CADMIUM, 



Stromeyer. Seht9. 22, 262; absir. GUb. 60, 193. 

Hermann. OUb. 59, 95 and 113; 66, 276. 

Meissner. Gilb. 59, 99. 

Roloff. BerL Jahrb. 1819, 250; OUb. 70, 194. 

Karsten. Archiv, /. Bergbau und BuUenwetm, 1, 209; abstr. BerL 

Jahrb. 1819, 244. 
John, ins. Handworterhuck der Chemxe, 3, 299; also Berl. Jahrb, 1819, 

245.— Further: Berl. Jahrb. 1820, 365. 
Children. FhU. Mag. No. 259, 63; also Schw.2^, 441. 
Clarke. Ann. FhU. 15, 272; also Schw. 30, 222.— Further: Ann. FhU. 

18, 123; 3, 195. 
Herapath. Ann. FhU. 19, 435. 



ST50NYMB8. XlaproAmniy MeUnum. 

History. Cadmium appears to have been discovered about the same 
time — in the spring of 1818 — hy Stromejer and by Hermann; the more 
accurate investigation of it is, however, due to Stromeyer. 



Sources. As sulphide of cadmium; — also in small quantity in several 
varieties of Calamine and Blende, namely, in the nidiated Blende of 
Przibram, to the amount of 2 or 3 per cent. (Stromeyer.) In the Blende 
of Nuissiere to the amount of 1-136 per cent. (Damour, «7. pr. Cheni. 13, 
354.) In silicate of zinc from Freiberg and from Derbyshire; in carbonate 
of zinc from Mendip: in carbonate and silicate of zinc from the Cumber- 
land mines; in commercial English zinc; but not in the carbonate of zinc 
from Holywell, or in the silicate from Hungary. (Clarke.) The flowers 
of zinc obtained in the preparation of zinc from calamine in Silesia 
(p. 1) likewise contain about 3 per cent, of cadmium. All these 
bodies, when heated in the inner blowpipe-flame, form a red deposit on 
charcoal or on platinum. 

Preparation, 1 . Cadmiferous zinc, oxide of zinc, or zinc ore, is dis- 
solved in dilute sulphuric acid; the solution supersaturated with acid; the 
cadmium precipitated by sulphuretted hydrogen; the sulphide of cadmium 
washed and dissolved in strong hydrochloric acid; the excess of that acid 
expelled by evaporation; and the cadmium precipitated as a carbonate 
by means of carbonate of ammonia, which is added in slight excess, in 
order to re-dissolve anv copper or zinc that may be mixed with the- 
cadmium. The oxide of cadmium, after being washed and then heated 
to redness to free it from carbonic acid, is mixod with thoroughly ignited 



CADMIC OXIDE. 53 

lamp-black, and heated to redness in glass or earthen retorts: the metal 
then distils over. (Stromeyer.) — John treats the cadmiferous zinc with a 
quantity of dilute sulphuric acid, not sufficient to dissolve it, — ^whereupon 
the dissolved cadmium is precipitated by the excess of zinc in grey 
flakes. These flakes are dissolved in dilute sulphuric acid — the solution 
evaporated to dryness — the residue dissolved in water — the solution 
acidulated with hydrochloric acid — and the cadmium precipitated from it 
by zinc. — 8. John treats the solution of cadmiferous zinc-flowers in 
sulphuric acid with sulphuretted hydrogen, in order to precipitate the 
cadmium in the form of sulphide— decomposes the precipitate with nitric 
acid— evaporates— dissolves the residue in dilute hydrochloric acid — ^and 
precipitates the cadmium by zinc. — 4. In the distillation of zinc in 
England, the cadmium- vapours, being the more volatile, pass over before 
the zinc- vapours, and burn with a brown flame, forming a yellow, brown, 
or black oxide, which, besides sulphide of cadmium, oxide of zinc, and 
carbon, contains about 20 per cent, of cadmic oxide, and consequently, 
when dissolved in hydrochloric acid and precipitated by zinc, yields a 
large quantity of cadmium, which may be purified hy sublimation. 
(Herapath.) — 5. In Silesia, cadmium is prepared on the large scale from 
flowers of zinc, by gently igniting them with charcoal powder in earthen 
tubes — collecting the metallic powder deposited in the receiver [still 
containing zinc to the amount of half its weight] and distilling it twice 
in the same apparatus — and finally fusing the sublimed metal in a crucible 
with tallow. (HoUunder, Kastn. Arch, 12, 245.) It is not easy to get rid 

of all the zinc by this process. 

« 

JProperties. Crystallizes readily in octohedrons ; has a dense texture 
and Indented fracture. Soft, but harder and more coherent than tin ; 
easily cut with the knife; very flexible; very easily beaten out into thin 
plates or drawn into wires. (Stromeyer.) "When bent, it emits a crackling 
noise like tin. Specific gravity after fusion, 8*604 (Stromeyer), 8*6355 
(Karsten), 8-67 (Children), 8677 (Herapath), 875 (John); after ham- 
mering, 8*6944 (Stromeyer), 9*05 (Children). Has a strong lustre. In 
colour it is intermediate between tin and zinc. Fuses below a red heat; 
volatilizes somewhat below the boiling point of mercury, and without 
emitting any particular odour. (Stromeyer.) 



Compounds of Cadmium. 
Cadmium and Oxygen. 

A, Suboxide of Cadmium ? 

Oxalate of cadmic oxide, heated in a retort to the melting point of lead, 
gives off water, carbonic acid, and marsh-gas, and is converted into a 
green powder. Mercury does not extract any metal from this powder. 
When heated in the air, it glows vividly, gives off a cloud of brown 
oxide, and leaves a mixture of metal and oxide, which partly fuses 
together in the form of golden-yellow grains of oxid& mixed with metal. 
When treated with dilute sulphuric acid, it effervesces slightly from the 
escape of carbonic acid still retained in it, and yields cadmic oxide to the 
acid, while metallio cadmium remains behind. By dissolving it in nitric 
acid, evaporating to dryness^ and igniting, 106*13 parts of cadmio oxide 



54 CADMHIH. 



[ 



are obtained: hence it contains 93*3 [92*9] par cent of metal asd 6*7 
7.1] of oxygen. (Marchand, Po^g. SB, 145.) Its composition is there- 
bre nearly Cd'O. 

B. Cadmic Oxidb. 

Protoxide of Cadmium^ Kadmiumoxyd, Oxyde cadmique. 

Cadmium becomes somewhat tarnished by exposure to the air. 
(Stromeyer.) In moist air free from carbonic acid^ it remains unchanged. 
When immersed in water and exposed to air free from carbonic acid, it 
becomes covered with a white powder, probably consisting of hydrated 
oxide; in air containing carbonic acid, it acquires a whitish-grey deposit, 
which contains carbonic acid. (Bonsdorff, Fogg. 42, 336.) When exposed 
to the air under water containing -j^ of potash hydrate, the metal 
becomes blackish-grey, but yellow after drying, and a trace of cadmio 
oxide dissolves in the water. (A. Vogel, J, pr. Ckem. 14, 107.) The 
metal bums easily when heated in the air, forming cadmic oxide, which 
rises in the form of a brownish -yellow, inodorous cloud. (Stromeyer.) 
At ordinary temperatures it does not decompose water, unless one ot the 
stronger acids, such as sulphuric, hydrochloric, or acetic acid is present, 
the decomposition then taking place with slow evolution of hydrogen 
gas. (Stromeyer.) Cadmium decomposes vapour of water at tempera- 
tures above the boiling point — as when a mixture of aqueous vapour and 
cadmium- vapour is passed through a red-hot tube — the products being 
cadmic oxide and hydrogen gas. (Regnault, Ann. Chim, Fhys, 62, 351.) 
It oxidizes and dissolves rapidly in cold nitric acid. (Stromeyer.) Cadmic 
oxide is obtained by burning cadmium, or by igniting the carbonate or 
nitrate. 

Cadmic oxide is a powder, sometimes of a brownish-yellow, sometimes 
of a brownish-red, and sometimes of a dark brown colour. Does not fuse, or 
volatilize, or decompose, even at the most intense white heat. (Stromeyer.) 
Specific gravity 6*9302. (Karsten.) Herapath, on subliming the metal 
in a glass tulie containing air, obtained the oxide in purple, opaqne 
needles, aggregated in stellate masses. 

Stromeyer. John. 

Cd 56 .... 87-5 87-45 90 — 91 

O 8 .... 12-5 12-55 10—9 

CdO 64 .... 1000 ZZ 100-00 100 — 100 

CdO = 696-77 + 100 « 796-77. (BcraeUus.) 

Charcoal withdraws oxygen from cadmic oxide at a low red heat. The 
cadmium, as it is reduced on charcoal before the blowpipe, is immediately 
burnt a^n, and produces a brownish yellow or a red film upon the 
oharcoaL 

ComhincUions, a. With water. — Hydrate of Cadmio Oxidb. — Formed 
by precioitating a cadmic salt in solution by caustic potash. % If the 
solution be concentrated, a basic salt is obtained j but from a dilute solu- 
tion, the hydrated oxide CdO,HO is obtained. (Schaffner, Ann. Pharm, 
51, 173.) H White; loses its water at a red heat; absorbs carbonic acid 
from the air. Y Nickl^s has obtained the hydrated oxide in the crystal- 
line state by the action of aqueous ammonia on metallic cadmium placed 
in contact with iron. The compound thus formed had nearly the oompo- 
sition CdO,HO. (J. Pkarm, [3 J, 12, 61.) IT 



CAPMIC SALTS. 55 

5. With Acids, forming the Salts of Oadmig Oxide, or Cadmig Salts. 
— ^These salts are mostly colourless ; those which are soluble in water, 
redden litmus; they have a disagreeable metallic taste, and act as emetics. 
They give off their acid by ignition^ provided the acid is volatile. 
Whenlieated with carbonate of soda on charcoal in the inner blowpipe* 
flame, they form a yellow or brown-red deposit on the charcoa]. The 
solutions of these salts give the following reactions : Zinc throws down 
metallic cadmium in dendrites. Clarke*s statement that cadmium is like- 
wise precipitated by iron, is contradicted by Meissner and Fischer. — Sul- 
phuretted hydrogen parsed through cadmic solutions, even when a large 
excess of acid is present, precipitates the whole of the cadmium in the 
form of sulphide, which has a lemon-yellow colour at first, but afterwards 
becomes orange-yellow. A similar effect is produced bv alkaline hvdro- 
sulphates, the precipitate being insoluble in excess. The hydrated sul- 
phides of manganese, iron, cobalt, and nickel, when recently precipitated, 
likewise throw down sulphide of cadmium from cadmic salts. (Anthon. 
J. pr. Ghem. 10, 353.) — Caustic alkalis throw down white hydrate of 
cadmic oxide, very easily soluble in a slight excess of ammonia, but in- 
soluble in potash or soda. Sulphuretted hydrogen likewise precipitates 
sulphide of cadmium from the solution in excess of ammonia. — The 
monocarbonates and bicarbonates of ammonia, potash, and soda, throw 
down white carbonate of cadmic oxide, insoluble ni excess of the alkaline 
carbonates. If the salt contains a large quantity of free acid, the preci- 
pitate dissolves in excess of carbonate of ammonia, but not otherwise. 
(Stromeyer.) — Phosphate of soda throws down white phosphate of cadmic 
oxide. — Oxalic acid and alkaline oxalates precipitate white oxalate of 
cadmic oxide, insoluble in alkaline oxalates, but easily soluble in ammonia. 
The white precipitate produced by ferrocyanide of potassium, and the 
yellow precipitate produced by the ferricyanide, are soluble in hydro- 
chloric acid.-— The siddition of hyposulphite of soda and hydrochloric acid 
does not produce a precipitate of sulphide of cadmium ; neither is any 
precipitate produced by chromic acid, succinic acid, alkaline beuzoates, 
or tincture of galls.^-Those salts of cadmium which are insoluble in 
water dissolve in sulphuric, hydrochloric, or nitric acid, and likewise in 
cold aqueous solution of sulphate, hydrochlorate^ nitrate, or benzoate of 
ammonia. 

c. With Ammonia and with Borax. 



Cadmium aiid Cabbon. 

Carbonate of Cabmio Oxidb, or Cadmic Carbonatb. — ^White 

powder^ anhydrous after drying, insoluble in water. (Stromeyer.) Specific 

gravity about 4'4938. (Karsten.) 

Stromeyer. John. 

CdO .« 64 .... 74-42 74-547 .... 72 

CO» 22 .... 25-58 25-453 .... 25 

CdO,CO» .... 86 .... 10000 ZZ 100000 Z 99" 

IT According to Lefort {J, Pharm. [3] 12, 406), the precipitate 
thrown down from. cadmium solutions by alkaline carbonates is 2(CdO, 
C0^)+ HO; and the whole of the water goes off between 80'' and 120^ 



56 CADMIUM. 



Cadmium and Boron. 

Borate of Cadmic Oxide or Cadmic Borate.— Bj precipitating 
monosulphate of cadmic oxide with borax. White powder, difficnltly 
soluble in water. Contains 72*115 cadmic oxide and 27*885 boracic aoio. 
(Stromejer.) 

Cadmium and Phosphorus. 

A. Phosphide of Cadmium. — Grey, with a faint metallic lustre; yeiy 
brittle and difficult to fuse. When heated in the air, it bums with a 
bright flame, and is converted into phosphate of cadmic oxide. Dissolyes 
in hydrochloric acid, with evolution of phosphuretted hydrogen. 

B. Hypophosphite of Cadmic Oxide or Cadmic Hypophosphitb. 
-—Aqueous hypophosphorous acid, saturated in the cold with excess of 
cadmic carbonate, then filtered and evaporated in vacuo, yields small 
crystals. These crystals, when heated in a retort, give off a considerable 
quantity of phosphorus in the form of a sublimate, and likewise a mixture 
of hydrogen and phosphuretted hydrogen— each bubble of which takes 
fire spontaneously — and leave a mixture of not quite 1 part of brown 
phosphoric oxide, and somewhat more than 99 parts of cadmic phosphate, 
in which 56*86 parts of cadmic oxide are united with 43'14 parts of 
phosphoric acid. (H. Rose, Pogg, 12, 91.) 

C. Phosphite of Cadmic Oxide or Cadmic Phosphite. — By double 
affinity, with sulphate of cadmic oxide and phosphite of ammonia. The 
white precipitate, ignited in a retort, gives off pure hydrogen gas, without 
evolution of light and heat, but with sublimation of a small quantity of 
metallic cadmium, and leaves a fused mass, black and blistered when 
solidified. (H. Rose, Fogg. 9, 41.) 

D. Ordinary Phosphate of Cadmic Oxide or Cadmic Phosphate. — 
By precipitating a cadmic salt with diphosphate of soda. White powder, 
insoluble in water. When heated to incipient whiteness, it fuses to a 
transparent glass. Contains 69*284 cadmic oxide and 30*716 phosphoric 
acid. (Stromeyer.) 

H E. Pyrophosphate of Cadmic Oxide or Cadmic Pyro- 
phosphate.*— By precipitating sulphate of cadmic oxide with pyro- 
phosphate of soda. White powder, which sinks slowly to the bottom of 
the liquid — soluble in ammonia, pyrophosphate of soda, and acids, but 
insoluble in caustic potash. When ignited in a current of hydrogen, it 
yields a sublimate of metallic cadmium and phosphorous acid, while a 
small quantity of phosphuretted hvdroeen is evolved, and a white mass 
is left, containing phosphoric acid and cadmic oxide. It dissolves In 
sulphurous acid, and is precipitated from the solution, on boiling, in 
laminsB having a mother-of-pearl lustre. 

Schwarzenbeig. 

2CdO 128-0 .... 6419 63-65 

6PO* yi-4 .... 35-81 36-3$ 

2CdO,6PO» 199*4 .... 100*00 100*00 

(Schwarzenberg, Ann^ Fharm. 65, 153.) IT 



CADMIC SULPHITE. 57 

F. Metaphobphatb of Cabmic Oxide or Cadmig Metaphosphatb. 
—Nitrate of cadmio oxide mixed, first with metaphosphoric acid, and 
then with ammonia, yields a precipitate which dissolves in excess of 
ammonia^ hut separates again when the solution is exposed to the air* 
(Persos^ Ann. Ckm. Fhys. 56, 334.) 

Cadmium aiid Sulphur. 

A. Sulphide of Cadmium. — Found native in the form of Cfreenockite, 
Prepared as a pigment known hy the name of Jaune brillant. Formed 
with difficulty hy fusing cadmium with sulphur, — ^more readily hy igniting 
cadmio oxide with sulphur ; precipitated in yellow flakes when hydro- 
sulphuric acid or an alkaline hydrosulphate is hrought in contact with a 
cadmium salt. The native sulphide crystallizes in douhle six-sided 
pyramids and other forms of the hexagonal system; cleavage parallel to 
the terminal and lateral edges of a six-sided prism. Specific gravity, 
4*8 (Brooke), 4*908 (Breithaupt). Hardness equal to that of calcspar. 
Of diamond lustre, semi-transparent, honey-yellow j yields an orange- 
yellow or a hrick-red powder ; hecomes carmine-red whenever it is 
heated. Decrepitates when heated somewhat strongly. (Brooke, Breit- 
haapt.) The artificial sulphide, in the precipitated state, is an orange- 
yellow powder, which, when heated to redness, hecomes first hrownish 
and then carmine-red. Fuses at an incipient white heat, and solidifies on 
cooling, in transparent, lemon-yellow, micaceous laminte. Not volatile at 
any temperature. (Stromeyer.) Specific gravity of the fused artificial 
sulphide, 4*605. (Karsten.) 

Stromejer. Connell. Thomson. 

Artificial. Native. Native. 

Cd 56 .... 77*77 .... 7802 .... 77*30 .... 77*6 

8 16 .... 22-22 .... 21-98 .... 22-56 .... 22*4 

f o ■■•■•••••••• •■•« •■•• •••• vrscw 



■••• 



CdS 72 .... 10000 .... 10000 .... 99*86 .... 100-0 

In dilute hydrochloric acid it dissolves with difficulty, even when the 
acid is heated; hut if the acid he strong, the sulphide dissolves with ease, 
even at ordinary 'temperatures, with violent evolution of sulphuretted 
hydrogen, and without separation of sulphur. (Stromeyer.) At a red 
heat, it slightly decomposes vapour of water; at a white heat, cadmio 
oxide is formed. (Reynault.) Dissolves in nitric acid, with evolution of 
sulphuretted hydrogen and separation of sulphur. (Meissner.) Very 
slightly soluhle in ammonia. (Wackenroder, Repert. 46, 226.) 

B. Sulphite of Cadmic Oxide or Cadmig Sulphite. — Cadmium 
dissolves in aqueous sulphurous acid, and forms sulphite of cadmic oxide, 
a large quantity of salphide of cadmium heing produced at the same time: 
for the hydrogen gas evolved hy the action of the sulphurous acid on 
the metal, acts while in the nascent state on a portion of the sulphurous 
acid, and forms hydrosulphuric acid ; and this, again, precipitates a por- 
tion of the dissolved cadmic oxide in the form of sulphide* (Fordos & 
Gelis, C<mpt. rend. 16, 1070; also J. pr. Ghent. 29, 288.) 

3Cd + 3H0 + 3S0» = 3(CdO, S0») + 3H ; 
and 3H + SO>»HS + 2HO; 

and 3(CdO, SO*) + HS = 2CdO, 3S0* + CdS + HO. 



58 CADMIUM. 

IT Carbonate of cadmie oxide ie readily dissolred by sulphnioiLB acid; 
and, on adding absolute aloohol to the solution, a precipitate resembling 
alumina is produoedi which does not give off water when heated in a 
(ube. If. this precipitate be left at rest in the li<}uid, beautiful silFeiy 
crystals are deposited, having the following composition : 

Muspntt. 

CdO 64 .... 55-99 

802 49 .... 28-19 27-98 

2HO 18 .... 15-82 15-90 

CdO,80« + 2Aq 130 .... lOOOO 

(Muspratt, Phil, Mag, 11, 414; Awn, Pharm. 64, 242.) IT 

C. Hyposulphate of Cadmic Oxide or Cadmio Htpostjlphatb. — 
The solution of cadmic carbonate in aqueous hyposulphuric acid deposits, 
when slowly cooled, a crystalline mass of salt, which has a very rough 
taste, is very easily soluble in water, and deliquesces in moist air. 



D. Sulphate of Cadmic Oxide or Cadmic Sulphate. — a,DisiUphale. 
-»1. By ignition of 6. (Stromeyer.) — 2. By imperfectly precipitating b 
with potash (Kiihn, Schw, 60, 344); — by exactly precipitating one- 
third of a solution of the neutral sulphate with caustic potash, and boil- 
ing the precipitate with the rest of the solution. (Kiihn, Pkarm. Centr, 
1847, 595.) Sparingly soluble in water; separates from the solution in 
scales. (Stromeyer.) 



2CdO 
SO* . 
HO . 







KUhn CI.) Ktthn (2.) 


128 


.... /Z'dZ 


7201 .... 72-6 


40 


.... 22-60 


21-96 .... 19-3 


9 


.... 608 


6-03 .... 8-1 



2CdO,80» + Aq 177 .... 10000 10000 .... lOO'O 

5. Monosulphaie. — Crystallises with water in large, transparent rect- 
angular prisms, resembling crystals of zinc-vitriol; they effloresce rapidly 
in the air [permanent in the air^ according to Meissner], and, when 
gently heated, give off their water of crystalliaition without fusing; 
when more strongly ignited, they lose half their acid, und are converted 
into a. Easily soluble in water. (Stromeyer.) 

Anhydroui, Stromeyer. Cry^tdUiMed. Stromeyer. 

CdO 64 .... 61-54 .... 617 CdO.... 64 .... 45*72 .... 45*956 

S0« 40 .... 38-46 .... 38-3 SO» .... 40 .... 2857 .... 28*523 

4HO.... 36 .... 25*71 .... 25-521 

CdO,SO> 104 .... 100-00 .... 100*0 •t-4Aq, 140 .... 100*00 .... 100000 

IT By evaporating a solution of cadmio sulphate containing excess of 
sulphuric acid, Kiihn obtained compact crusts of indistinct crystals, con« 
tainingCdO,SO»+HO. {Pharm. CerUr, 1847, 595.) IT 

E. SuLPHOCARBONATB OF Cadmivm. — Hydrosulphocarbonatc of cal- 
cium gives, with cadmic salts, a lemon-yellow precipitate, slightly soluble 
in water, to which it imparts a yellow colour. (Benelius.) 



BROMIDB OF CADMIUIC fi9 



Cadmium akb Sblenium. 

IT Selenite of Gadmio Oxide or Cadnio Sblbnite. — Selenious aoid 
does not preoipitate salts of cadmiam. Selenite of ammonia gives, with 
chloride of cadmium, a white precipitate, having an argillaceous appear- 
ance, and assuming an orange tint when exposed to the air. The salt 
contains no water. It is soluble in selenious acid. When heated in a 
tube, it yields a yellowish-red sublimate. (Muspratt, Ghem* Soc, Qu. </, 
II. 65.) IT 

Cadmium akd Iodine. 

A. Iodide of Cadmium. — Prepared either in the dry way or by 
digesting cadmium with iodine and water. Fuses very easily. Crystal- 
lizes on cooling from the fused state, or from an aqueous or alcoholic 
solution, in large, transparent and colourless, six-sided tables, which are 
permanent in the air, and have a metallic lustre inclining to that of 
mother-of-pearl. — When somewhat strongly ignited [in the airl], it 
evolves iodine. Dissolves readily in water and alcohol, and crystaliizes 
from these solutions, on evaporation, still in the form of iodide of cad- 
mium. Sulphuretted hydrogen passed through the solution slowly preci- 
pitates sulphide of cadmium. (Stromeyer.) 

Stromeyer. 

Cd 56 .... 30-77 3054 

I 126 .... 69-23 69-46 

Cdi 182 .... 10000 ZZ 10000 

B. loDATB OF Cadmio Oxide or Cadmio Iodate. — Concentrated 
solutions of iodate of soda and iodate of cadmic oxide immediately form 
a precipitate soluble in excess of the cadmic salt; it is bulky at first, but 
soon falls together in the form of a crystalline meal. When dry, it 
forms a white anhydrous powder. This powder, when heatedfin a retort, 
gives off ox3'gen gas and iodine vapour, and leaves a brownish-red 
mixture of oxide and iodide of cadmium, from which water extracts 
nothing, but nitric acid liberates iodine. — The powder dissolves but very 
sparingly in water^ more readily in nitric acid and ammonia. 

Cadmium and Bromine. 

A. Bromide of Cadmium. — 1 . At ordinary temperatures, cadmium 

does not combine with bromine; but when heated nearly to redness, it 

absorbs vapour of bromine, forming white fumes of bromide of cadmium. 

2. Hydrated bromide of cskdmium is converted by heat into the anhydrous 

bromide. — Bromide of cadmium fuses readily [and crystallizes on cooling; 

Crofi]^ and, when strongly heated, sublimes in white rounded laminie 

having a mother-of-pearl lustre. It is decomposed b^ heated nitric acid, 

but dissolves without decomposition in hydrochlonc acid, acetic acid^ 

alcohol, and ether. 

Berth^mot 

Cd 56-0 .... 41'66 41-47 

Br 78-4 .... 5834 58*53 

GdBr..... 134-4 ..,. 100-00 .....„• 100-00 



60 CADMIUM. 

Hydraied Bromide of Cadmium or HydrohromcUe of Cadmic Oxide,'^^ 
Bromide of cadmium dissolves easily in water. The solution may be 
formed by digesting cadmium with bromine and water. When evapo- 
rated and cooled, it yields white^ efflorescent needles. These crystsols 
give off half their water at 100'', and the rest, without fusing, at 200% 
whereupon they assume an enamel-like appearance. (Rammelsberg, Poff^. 
65, 241.) When suddenly heated, they fuse in their water of crystalli- 
zation, and are converted into anhydrous bromide of cadmium. (Berthe- 
mot; comp., Croft, FhU. Mag, J. 21, 356.) 

CryitalltMed. Croft. RammeUbeig. 

CdBr 134-4 .... 78*87 7905 .... 80-5 

4H0 36-0 .... 21-13 20-95 .... 19*5 

CdBr + 4Aq. .... 1704 ....100-00 ZZ 10000 Z. 1000 

B. Bromate of Cadmic Oxide or Cadmic Bromate. — Formed by pre- 
cipitating sulphate of cadmic-oxide with bromate of baryta, and evaporat- 
ing the filtrate over oil of vitriol in a receiver containing air. — Transpa- 
rent, rhombic prisms with angles of 127° and 53"", having their lateral 
edges truncated, and bevelled with two narrow faces; terminated with 
four-sided summits. The crystals, when heated, give off bromine yapour 
and oxygen gas, and leave a brown mixture of oxide and bromide of 
cadmium, the latter of which may be dissolved out by water. They 
dissolve in 0'8 pt. of cold water. (Rammelsberg, Foyg, 55, 74.) 

CrytialUzed. Rammdaberg. 

CdO 64-0 .... 33*44 33*38 

BrO« 118-4 .... 61-86 61-92 

HO 9-0 4-70 4-70 

CdO,BrO» + Aq 191-4 .... 10000 10000 



Cadmium and Chlorine. 

A . Chloride of Cadmium. — Formed by fusing the hydrochlorate of 
cadmic oxide. After fusion it presents the appearance of a transparent 
mass, having a metallic, pearly lustre and lameilated texture; crystallizes 
by sublimation in transparent, micaceous laminsB having a similar lustre. 
Fuses at a heat below redness, and volatilizes at a somewhat higher 
temperature. — When exposed to the air, it loses its transparency and 
lustre, and crumbles to a white powder. (Stromeyer.) 



Cd 


56-0 


.... 
.... 


61-27 
38-73 


Stromeyer. 
61-39 


CI 


»....M*... Ou 4 


38-61 



CdCl 91-4 .... 100-00 100-00 

HydraUd Chloride of Cadmium or Hydrochlorate of Cadmic Oxide.^^ 
Transparent rectangular prisms which deliquesce readily when heated, 
and are easily soluble in water. (Stromeyer, John.) 

Perchlorate of Cadmic Oxide or Cadmic Perchlorate. — The 
solution of the oxide in aqueous perchloric acid leaves, when evaporated 
in the hot. air chamber, a transparent, deliquescent, crystalline mass, 
which is soluble in alcohol. (Sernllas^ Ann, Chim. Fhy$, 46, 805.) 



CADMIUM AND NITROGEN. 6 1 ' 



Cadmium and Flitorins. 

Fluoridb op CADMinM.-*>Depo8ited from the aqneona solntion^ on 
evaporation^ in white, indistinctly crystalline crusts, which adhere firmly 
to the sides of the vessel. Sparingly solnble in pure water, more readily 
in aqueous hydrofluoric acid. (Berzelius, Fogg. 1, 26.) 



Cadmium ai^d Nitrogen. 

A. NUride of ^a^mtt^m ^—Obtained in the same manner as nitride 
of zinc (p. 33). The solution must always contain an excess of sal- 
ammoniac. The liquid becomes turbid [in the preparation of zinc-nitride 
it remains clear], because the ammonia, as it is set free at the negative 
pole, precipitates hydrated cadmic oxide, which, however, in the imme- 
diate neighbourhood of the pole, is re-dissolved by the ammonia subse- 

Suently liberated. On the negative pole there is soon deposited a spongy, 
ark, lead-grey, non-crystalline mass, which visibly increases, and, after 
being pressed between two plates of glass, has the appearance of a lead- 
grey amalgam : when washed and dried, it has a specific gravity of 4*8. 
Five j^rains of this substance yield, when heated, from 0*18 to 0*25 cub. 
in. of nitrogen gas free from hydrogen, and leave a yellowish-green 
residue containing globules of metallic cadmium. (Grove, Phil, Mag. J, 
19, 99; also Pogg. 54, 101.) 

B. Nitrate op Cadmic Oxide, or Cadmic Nitrate.— Crystallizes 
in combination with water, in prisms and needles united in radiated masses 
(Stromeyer), which deliquesce in the air (Meissner), and dissolve in 
alcohol, but do not impart any peculiar colour to its flame. (Children.) 

Anhydrous. Stromeyer. CrystaUixed, Stromeyer. 

CdO 64 .... 54-24 .... 5409 CdO.... 64 .... 4156 .... 4215 

NO» 54 .... 45-76 .... 45-91 NO*.... 54 .... 35*07 .... 3578 

4HO 36 .... 23-37 .... 2207 

CdO,NO» 118 .... 100-00 .... 10000 +4Aq. 154 .... 10000 .... 10000 

C. Ammokiacal Oxide of CADMiVM.-^Aqneous ammonia readily 
dissolves cadmic oxide — the oxide first turning white— and deposits it, 
on evaporation, in the form of a gelatinous hydrate. (Stromeyer.)—- 
Potash precipitates cadmic oxide from its solution in ammonia. 

D. Ammoniacal Hyposulphatb op Cadmtc Oxide. — The solution of 
cadmic hyposulphate in heated ammonia, when left to evaporate spon- 
taneously, deposits the compound in the form of a crystalline meal, mixed, 
however, — since some amount of decomposition takes place on evapora- 
tion — ^with hydrate and hyposulphate of cadmic oxide. (RammeLsberg, 

Pogg. 58, 298.) 

RammeLiberg. 

2NH» 34 ...• 2000 1832 

CdO 64 .... 37-65 3812 

S»0* 72 .... 42-35 

2NH' + CdO,yO» 170 .... 100-00 



6i CADMIUM. 

E. Ahmonio-sulphate of Cadmtc Oxide.— 100 parts of anhydrous 
cadmic sulphate absorb 48*69 parts (8 At.) of ammonia, with great rise 
of temperature and tumefaction, and are thereby converted into a white 
powder. The compound, when heated to redness, gives off a large quan- 
tity of ammoniacai gas, and yields a trifling sublimate of sulphite of 
ammonia. It dissolves in water, with separation of cadmic oxide. (H. 
Rose, Po^g, 20, 152.) 

H. Rose. 

3NH> 51 .... 32-9 32-74 

CdO,SO» 104 .,.. 67-1 67-26 

3NH»+CdO,SO».... 155 .... 1000 ZZ 10000 

F. Ammonio-iodidb op Cadmium. — a, 3NH',CdI. — Dry iodide 
of potassium does not absorb ammoniacai gas at ordinary temperatures; 
but when gently heated, it takes up 27*789 per cent, of ammonia, swelling 
up and evolving heat, and crumbling to a fine white powder. The com- 
pound gives up all its ammonia when heated. Water added to the powder 
separates hydfrated oxide of cadmium, with which a small portion of 
iodine still remains^-and forms a solution containing a small portion of 
cadmium, and giving off ammonia when heated. (Rammelsberg.) 

b. NH',CdI. — A solution of iodide of potassium in heated ammonia 
deposits very small crystals on cooling, and the mother-liquid, if evapo- 
rated and mixed with ammonia, yields an additional quantity. The 
crystals fuse when heated, giving off ammonia and water — which is not 
essential to tlieir constitution— and leaving iodide of cadmium. They 
are decomposed by water in the same manner as a. (Rammelsberg, 

PoffSf' 48, 153.) 

a, Rammelsberg. 

3NH3 51 .... 21-80 21-75 

Cdl 182 .... 78-11 78-25 

3NH',CdI 233 Z 10000 ZZ 10000 



Cdl 
HO.. 





h. 




Rammelsberg. 


17 


• ••• 


8 54 


715 


182 


• •■• 


91-46 


91-37 




• •«• 


• 


1-48 



NH»,CdI 199 .... 10000 10000 

When a solution of cadmic iodate in aqueous ammonia is left to 
evaporate freely, it yields — ^besides crystals of iodate of ammonia— crys- 
talline crusts, which probably contain ammoniacai iodate of cadmic oxide. 
(Rammelsberg.) 



G. Ammonio-bromidb op Cadmium. — a, 2NH',CdBr. Dry, pul- 
verized bromide of cadmium swells up when introduced into ammoniacai 
gas, taking up 2 atoms of ammonia (from 2 to 3 : Crofi,), and crumbling 
to a bulky white powder. The compound gives off all its ammonia when 
heated; on dissolving it in water, part of the oxide separates out. (Ram- 
melsberg.) — 6. NH',CdBr. A concentrated solution of bromide of cad- 
mium saturated with ammonia, yields, on evaporation, small crystals, 
which behave like a when heated, or when digested in water. (Rammels- 
berg, Fogg. 55, 241.) A solution of bromide of cadmium in warm aqueous 
ammonia deposits the compound in crystalline grains when rapidly cooled, 
and in regular octohedrons by slow cooling. (Croft, Phil, Mag, J, 21, 
B5G.) 



CADMIUM AND POTASSIUM. 6d 

2NH" 340 .... 20-19 22-26 

Cd 560 .... 33-25) -, -. 

Br 78-4 .... 46'56f '* *^ 

2NH»,CdBr 168-4 .... 100-00 ~.. 10000 

h. Rammelaberg. Croft« 

NH» 170 .... 11-23 10-66 .... 1169 

Cd 66-0 .... 36-99 38-19 

Br 78-4 .... 5178 

NH»,CdBr 151-4 .... 10000 

H. Ammonio-bkomate of Cadmic Oxide. — The concentrated sola- 
tion of cadmic bromate, mixed with a quantity of ammonia sufficient to 
Te-dissolve the precipitate formed by the first portions, and then eva- 
jporated under a receiver containing lime, yields crystals. The mixture 
is decomposed, both when eyaporated by heat, and when diluted with 
water, — white flakes of hydrated cadmic oxide, free from bromine, being 
deposited. (Rammelaberg, Fogg, 55, 74.) 

Calculaiion. 

3NH» 510 12-27 

2CdO 1280 30-78 

2BrC)» 236-8 56-95 

3NH»+2(CdO,BrO*) 415-8 10000 

I. Ammonio-chloride op Cadmium. — a. 8NH',CdCl. — 100 parts 
of pnlverized dry chloride of cadmium absorb 53'56 parts (about 3 At.) 
of ammonia, the absorption being slow at first, but afterwards rapid, and 
attended with rise of temperature and tumefaction. The compound, when 
exposed to the air, gives ofi" ammonia till it has lost its odour, and is con- 
verted into the following compound : — 6. NH',CdCl. — Chloride of cad- 
mium treated with aqueous ammonia yields a white powder, which dis- 
solves on the application of heat, and is deposited in the form of a 
crystalline powder on cooling. When heated, it gives off 1 6-63 per cent. 
(1 At.) of ammonia, mixed^ however, with a small portion of sal- 
ammoniac ; consequently, the residue is no longer soluble in water. 
(Croft, Fhil. Mag. J. 21, 355.) 

K. Chloride op Cadmium and Ammonium. — NH*Cl,CdCl. — A 
concentrated solution of chloride of cadmium and sal-ammoniac in equal 
numbers of atoms yields, at first, silvery needles containing 1 atom of 
water; these, however, gradually disappear, and are replaced by large 
anhvdrotts rhombohedrons, slightly soluble in alcohol and wood-spirit. 
(Croft.) 

Pure hydrated Carbonate and PhosphaJte of Cadmic Oxide dissolve 
readily in sulphate, li3'-drochlorate, nitrate, and succinate of ammonia. 
(Wittstein, liepert 57, 82.) 



Cadmium and Potassium. 

» 

A. Sulphate op Cadmic Oxide and Potash. — Yields erystale 
having the f<^m of sulphate of magnesia and aoftHio&ia. (Mitscberli<».) 



64 OADMIUM. 

B. Iodide op Cadmium and Potassium. — KI,CdI.--Not cmtal- 
lizable; very easily soluble in water,— slightly soluble in alcohol and 
wood-spirit. (Croft.) 

C. Bromide op Cadmium and Potassium. — KBr,CdBr. — Hydrated 
needles, very easily soluble in water, slightly soluble in alcohol. (Croft.) 

D. Chloride op Cadmium and Potassium. — KCl,CdCl. — Yields 
anhydrous and hydrated crystals, analogous to those of chloride of cad- 
mium and ammonium. Dissolves in water less readily than C ; slightly 
soluble in alcohol and wood-spirit. (Croft.) 

Cadmium and Sodium. 

Carbonate of soda does not dissolve cadmic oxide before the blow^* 
pipe. 

A. Melted Borax dissolves the oxide, forming a clear glass, which is 
yellowish while hot, becomes almost colourless on cooling, and if mode- 
rately charged with oxide, becomes milk-white by gentle flaming, but if 
more strongly charged, assumes an enamel- white appearance on simple 
cooling; if heated on charcoal, it boils continuously in consequence of 
the reduction and volatilization of the cadmium. 

B. Miorocosmic Salt dissolves the oxide abundantly, forming a clear 
glass, which, if saturated, becomes milk-white on cooling. (Berzelius.) 

C. Chloride op Cadmium and Sodium. — NaCl,CdCl. — Warty 
crystals, containing 3 At. water, soluble in 1*4 parts of water at 16**; 
slightly soluble in alcohol and wood-spirit. (Croft.) 



Cadmium and Calcium. 

ffypophosphUe of Cadmic oxide and Lime? — Bv boiling cadmic 
oxalate in excess with hypophosphite of lime and water, and eva- 
porating the filtrate in vacuo, a crystalline mass is obtained, which, when 
heated in a retort, gives off spontaneously inflammable phosphuretted 
hydrogen gas, a character by which it is distinguished from pure cadmic 
hypophosphite. It contains : hypophosphite of lime, 3*74; hypophosphite 
of cadmic oxide, 68*80 ; water, 27*46 (4 At.). (H. Rose, Po^g. 12, 294.) 

Cadmium and Silicium. 

Hydrated Silico-Fluoride of Cadmium. — Long, transparent, and 
colourless prisms, which are very easilv soluble in water, and efiloresce in 
warm air, forming an opaque, easily disintegrated mass. (Berzelius, Pogg. 
1, 199.) 

Cadmium and Tungsten. 



A. TuNosTATE OP Cadmic Oxide.— ^. MonotungstoJU. — Monotungstate 
of potash or soda added to a cadmic salt, throws down a white powder, 
which gives off its water when heated, assuming a reddish or yellowish 



CADMIUM AND ARSENIC. 65 

colour, and afterwards, when heated to redness, becomes blaish-black, 
and bakes together into a hard mass. It dissolves in phosphoric acid, 
oxalic acid, and ammonia, bat not in water. — h. Bitungstate. By preci* 
pitating with an alkaline bitungstate. The white pulverulent precipitate 
IS anhydrous; when ignited, it turns grey and bakes together. Soluble 
in phosphoric, oxalic, acetic acid, and ammonis^ but not in water. ( Anthon, 
J. pr. Ghent. 9, 341.) 

a. Ignited. Anthon. 

CdO 64 .... 34-78 .... 3587 

W(y 120 .... 65-22 .... 6413 

CdO,WO» 184 .... 10000 Z 10000 

a. Hydratid. Anthon. 

CdO 64 .... 31-68 .... 33 

WO* 120 .... 59-41 .... 59 

2HO 18 .... 8-91 .... 8 

CdO,WO» + 2Aq 202 Z. 10000 Z. 100 

B. SuLPnoTUNQSTATE OP Cadmiuh. — CdS,WS'. — On mixing the 
solution of a cadmic salt with sulphotungstate of potassium, this com- 
pound is immediately precipitated in the form of a lemon-yellow powder. 
(Berzelius.) 

Cadmium and Molybdenum. 

A. MoLYBDATE OP Cadmic Oxide. — Molybdato of ammonia gives, 
with sulphate of cadmic oxide, a greyish white precipitate which turns 
brown when gently ignited. (Brandes.) 

B. SuLPHOMOLYBDATE OP Cadmium. — By precipitating a cadmic salt 
with sulphomolybdate of potassium. Dark-brown precipitate, insoluble 
in water. (Berzelius.) 

C. Persulphomolybdate op Cadmium. — By precipitating with per- 
sulphomolybdate bf potassium. Red precipitate. (Berzelius, Pogg. 7, 
286.) 

Cadmium and Vanadium. 

Vanadiate op Cadmic Oxide. — a, Monovanadiate. — On mixing 
concentrated solutions of an alkaline monovanadiate and a cadmic salt, 
a portion is immediately precipitated in the form of a yellow substance 
which gradually turns white; the greater part of the salt is subsequently 
deposited as a white crystalline crust. — h. Bivanadiate. — Soluble in water. 
(Berzelius.) 

Permanganate of Potash does not precipitate hydrochlorate of cadmic oxide. 



Cadmium and Arsenic. 

A. SuLPHARSENiTE OP Cadmium. — By precipitating a cadmic salt 
with a saturated solution of sulpharsenious acid in hydrosulphate of 
ammonia. The pale yellow precipitate — orange-yellow when dry — 
becomes semi-fluid when heated, and is conyerted, by loss of orpiment, 

VOL. V. *■ 



66 TIN. 

into a swollen^ metal -grey eomponnd of sulphide of eadmiam with a 
small qaantity of orpiment^ which forma a deep-yellow powder. (Bm^ 
seliufl, Fogg, 7, 146.) 

B. SuLPHARSENTATE OF Cadmium. — Aqueous sulpharoeniate of sodium 
gives a light yellow precipitate with cadmic salts. (Berselius^ ^^99* ^% ^^O 

Cadmium and Antimony. 

SuLPHANTiHONiATE OP Cadmium. — The solation of Schlippe's salt 
gives a light orange^yellow precipitate with cadmic salts, if the former be 
in excess; bat if the cadmio salt is in excess, the precipitate is darker in 
colour and becomes red-brown after remaining for some time immersed in 
the liquid. (Rammelsberg, Fogg, 52, 236.) 

Cadmium and Tellurium. 

SuLPHOTELLURiTE OF Cadmium. — Analogous to the cerium-compound 
(IV. 425). 

Other Compounds of Cadmium. 

With Copper, Mercury, and Platinum. 



Chapter XXX. 

T I N, 



Proust. J. Phys. 51, 173; also Scher, J, 8, 481.— J. Phyi. 61, 338; also 

N, GchL 1, 249; also Gilb. 25, 440. 
Berzelius. Schw, 6, 284. — Further: Ann. Chim, Phys, 5, 141; also 

iV^. Tr. 2, 2, 359. 
J. Davy. Schw. 10, 321. 
Gay-Lussac. Ann. Chim. Phys. 1, 40. 



Stnontmes: Etain, Zinn, Stannum, JttpUer. 

History. Tin was known in the metallic state as early as the time 
of Moses; it was imported by the Phoenicians from Spain and England. 
Bichloride of tin was discovered in the sixteenth century by Libavius. 
The preparation of Mosaic gold was taught by Kunkel. The chief con- 
tributions to our knowledge of the compounds of tin have been made by 
Pelletier, Proust, J. Davy, and Benelius. 

Sources. Most frequently, as binoxide, in Tin-stone; rarely with 
sulphur and copper, in Tin-pyrites. In very small quantities, as binoxide, 
in the Seidschiitz water, and in many meteoric stones (Berzelius); in 
Manganesian Epidote and native peroxide of manganese {Braunstein) 
from Piedmont, and in all Scandinavian Epidotes. (Sobrero.) 



TIN. 67 

Preparation on Hie large scale. Tin-etone is bioken up— roasted to 
drive off the sulphur and arsenic of the ores that are mixed with it, and 
convert the other metals into light oxides easily separated from the 
heavier tin-stone by washing — and then fused in contact with charcoal^ 
either in smelting furnaces or in reverberatory furnaces, sometimes with 
the addition of a calcareous flux. — Purification on the large scaU, — 1. By 
gentle heating, whereby the purer tin fuses and runs off, while the more 
refractory alloys of tin and the foreign metals remain unmelted. — 2. By 
fusion, with imperfect access of air, whereby the foreign metals, together 
with a portion of the tin, are oxidized fir6t.-<*>The purest varieties of tin 
are Malacca and Banca tin and English Grain^tin; then follows Common 
English Grain-tin; then English Block-tin and Saxon and Bohemian 
Mine-tin (Bergzinn) ; then Tin -refuse and Tin-scum {Abgangs-und 
Ahstrich'zinn). The impurities consist of arsenic, antimony, bismuth, 
zinc, lead, iron and copper; they remain for the most part in the form 
of a black powder, on dissolving the tin in hydrochloric acid. The 

freater part of the arsenic is, howeyer, evolved in the form of arseniuretted 
ydrogen gas, and may be detected by Marsh's process. Stiiremberg 
{Ann, Pharm. 29, 216) found arsenic in all commercial tin, and likewise 
in tin-foil and tin-plate; a sample of Banca tin and likewise of English 
grain-tin were, however, found to be free from arsenic. Chevallier 
{J. Chim. Med, 16, 250) likewise obtained arseniuretted hydrogen gas on 
dissolving Banca tin which was said to be free from arsenic and did not 
deposit any black powder when dissolved. — Purification on the small 
scalf. — This is effected by oxidizing tin-filings with excess of nitric acid, 
washing the resulting binoxide with hydrochloric acid and water, and 
reducing it in a closed charcoal crucible at a low white heat. If pure 
water be used in the washing, the stannic oxide retains oxide of copper. 

Properties, Crystalline system the square prismatic When a feeble 
current from a Daniell's battery (I. 421) is passed through aqueous 
hydrochlorate of stannous oxide, the positive pole being formed of a 
plate of tin, the negative polar wire becomes covered, in the course of 
four days, with perfect crystals belonging to the square prismatic system. 
Fig, 39, without the jp face, but having the four a-faces and likewise 
eight acumination-faces resting upon e and a, Macle-crystals are of 
frequent occurrence. (Miller, Phil, Mag. J, 22, 263.) Mather {SUl. Ann, 
J. 27, 254) likewise obtained right-angled four-sided crystals of metallic 
tin, upon a piece of the metal immersed in a solution of the proto* 
chloride. Brooke obtained eight-sided needles by slowly cooling melted 
tin, and pouring off the portion which remained liquid. Pajot, on the 
other band {J. Phys. 38, 52), obtained rhombic tables by this process; 
and Breithaupt {Schw, 52, 171) saw tin from a Cornwall tin-furnace 
crystallized in short, regular, six-sided prisms. These crystals were 
regarded by Miller as CuSn*. Frankenheim {Poqg, 40, 456 j concludes, 
from the angles of the dendrites in the tin-tree, that the crystals belong 
to the regular system. — Specific gravity of tin-crystals =7*178, and after 
fusion and solidification, 7*293 (Miller); of tin solidified from fusion, 
7-291 (Brisson), 72911 (Kupffer), 7-2005 (Karsten); of rolled tin, 7*299 
(Brisson). Softer than gold, harder than lead; fracture indented. 
Decrepitates when bent. This crackling of tin {Geshrei des Zinnsi) is 
produced by the displacement of the crystals of which it is made up. 
Tin cannot be drawn out into fine wire, but may be beaten out into thin 
plates {Tin-foil). Bluish-white, with a strong lustre. Melts at 222-5** 

f2 



68 TIN. 

(G. A. Ennan), at 238° (Crichton), at 230° (Kupffer), at 267° (Morveau), 
and contracts slightly in cooling f Marx). Boils at a white heat. The 
disagreeable odour ascribed to tin does not properly belong to the metal 
itself, but is solely due to its action on animal substances, the fingers for 
example, with which it comes in contact. — Nitric acid of moderate 
strength attacks tin with violence, but without dissolving it, and converts 
it into a white powder. Tin may also be easily distinguished from other 
metals by its behaviour with a solution of gold containing excess of 
hydrochloric acid; a bright surface of tin immersed in such a solution, is 
blackened without CTolution of gas; zinc turns black and liberates gas; 
lead does not blacken. (Friedemann^ Repert, 77, 224.) 



Compounds of Tin* 

Tin and Oxygen. 

A. Stannous Oxide. SnO. 

Protoxide of Tin, Zinnoxydvl, Oxyde Stcnneux. 

Formation* Tin slowly decomposes water mixed with hydrochloric 
acid, sulphuric acid, or potash, and dissolves in these substances in the 
form of stannous oxide. The hydrogen which is evolved contains arsenic, 
if that metal is present in the tin. The aqueous solutions of sal-ammoniac, 
common salt, bisulphate of potash, alum, cream of tartar and borax-tartar 
likewise dissolve small quantities of tin when heated, and form solutions 
of stannous oxide; tin is also dissolved, though in very small quantity, 
by the aqueous solutions of nitrate of soda, monotartrate of potash, and 
Rochelle salt Solutions of carbonate of potash, sulphate of soda, 
chloride of barium or calcium, sulphate of magnesia, and tartrate of potash 
-and ammonia do not retain tin in solution, but in contact with air produce 
a deposition of stannic oxide. Nitre, borax, and diphosphate of soda 
have no action upon tin. (Lindes, Berl. Jahrh, 32, 2, 99; Cludius, J. pr, 
Chem, 9, 161.) 

Preparation. 1. Stannous oxide is precipitated in the form of hydrate 
from its solution in hydrochloric acid by the addition of carbonate of 
potash in excess — the hydrate quickly washed with thoroughly boiled 
water, and as much as possible out of contact of air — then dried at a 
temperature not exceeding 80° — and lastly freed from water by heating 
it in a retort completely filled with it, and having the air replaced by 
hydrogen or carbonic acid gas. (Bcrzelius.) — 2. Hydrochlorate of stan- 
nous oxide is treated with excess of ammonia, and the precipitated 
hydrate of stannous oxide boiled quickly for awhile to convert it into 
the anhydrous oxide, which is then quickly washed and dried. (Gay- 
Lussac.) — 3. Aqueous hydrochloric acid is saturated with tin; the solu- 
tion evaporated in contact with a piece of metallic tin, till a residue of 
fused protochloride of tin is left; the metal then taken out; 1 At. of the 
chloride of tin (94-4 parts) mixed in a mortar with 1 At. (143*2 parts) 
or more of crystallized carbonate of soda; the fluid mixture heated in a 
basin — with constant stirring — till it has become black through and 
through; the chloride of sodium, after cooling, extracted with boiling 
water; the stannous oxide washed with boiling water on the filter, and 



STANNOUS SALTS. 69 

lastly dried at a gentle heat. (Sandall, FkU. Mag, J, 12, 216; also J. 
pr. Ckeni, 14, 254.) This is a yerj advantageous mode of preparation. 
(Bottger, Ann. Pharm. 29, 87.) 

PropeHies, Black powder, of specific gravity %'Q(S^', brown-greenish- 
grey when poanded. (Berzellus.) Olive-green. (Gay-Lussac.) Bluish- 
black or slate-grey. (Sandall.) When hydrate of stannous oxide is boilnd 
with a quantity of potash not sufficient to dissolve it, the undissolvea 
portion is converted into small, hard, shining, black crystals of anhydrous 
stannic oxide, which, when heated to 200*^, decrepitate, swell up, and 
fall to pieces, and are converted into the olive-green protoxide like that 
obtained by Gay-Lussac. On evaporating a very dilute solution of sal- 
ammoniac in which hydrated protoxide of tin is diffused, that compound 
is converted, as soon as the sal-ammoniac crystallizes, into the anhydrous 
protoxide, having the form of a cinnabar-coloured powder, which, by 
friction with a hard body, is immediately converted into the greenish- 
brown binoxide. There are therefore three modifications of stannous oxide : 
crystallized, olive-green, and red. (Fremy, Compt, rend, 15, 1107; also 
N. J. Pharm. 3, 28.) — IT Roth {Ann. P/iarm, 60, 214) obtains the red 
modification by thoroughly washing the white hydrate of stannous oxide 
and digesting it at a temperature of 56^ with a solution of that oxide in 
acetic acid, the acid being slightly in excess and the solution having a 
specific gravity of 1 '06. The stannous oxide is then converted into heavy, 
hard, crystalline grains which yield a greenish-brown powder by tritura- 
tion ; they take fire when heated, and soon blacken by exposure to sun- 
shiue. With chemical re-agents, they behave like stannous oxide. IT 

Berzelios. J. Davy. Gay-Lussac. Proust. 

Sn 59 .... 88-06 .... 88-028 .... 88-01 .... 88106 .... 87 

8 .... 11-94 .... 11-972 .... 11-99 .... 11-894 .... 13 

SnO 67 .... 100-00 Z. lOO'OOO .... 10000 .... 100000 .... 100 

(SnO = 735-29 + 100 = 83529. Berzelius.) 

Decompositions, Reduced to the metallic state, by charcoal at a strong 
red heat; by potassium at a moderate heat, and with combustion. By 
sulphur it is converted into sulphide of tin, with evolution of sulphurous 
acid; and by boiling with a small quantity of potash-ley, into metallic 
tin and stannic acid, the latter dissolving in the potash. 

Combinations, a. With Water. — Hydrate of Stannous Oxide. 
When a solution of protochloride of tin is mixed with excess of carbonate 
of potash, or with excess of ammonia, the hydrated protoxide is pre- 
cipitated in the form of a brilliant white powder, containing, according to 
Proust, 5 per cent, of water, which, according to Berzelius, it gives up 
when gently heated, or even when boiled with water. — IF According to 
Schaffner, the precipitate formed by ammonia is not the hydrate, but a 
basic salt. The composition of the hydrate is 2SnO,HO. ^ 

h. With Acids, forming the Salts op Stannous Oxide or Stannous 
Salts. — Protosalts of Tin. — These salts are obtained by dissolving 
metallic tin, the protoxide, or its hydrate — which is more easily soluble 
— in acids. Most of them are either colourless or yellowish, redden 
litmus, and have a very disagreeable metallic taste. They rapidly 
abstract oxygen from the air and other ox3'gcn compounds, and are 
thereby converted into stannic salts; hence they give a purple or browu 



70 TIN, 

precipitate witK chloride of ^old, &c. [For a more detailed description of 
this, vid. Protoehlorids of Tin,"] Those which contain a volatile acid, 
give it off at a red heat, and, if the air has access to them, are converted 
into stannic oxide. With carbonate of soda upon charcoal in the inner 
hlowpipe-flame, they yield globules of metallic tin. — Zinc and cadmium 
immersed in the aqueous solutions of these salts precipitate the tin in an 
arborescent form: ike Tin-tree^ Arbor Jovis, Acetate of stannous oxide, 
however, is not reduced by tin or cadmium. Iron reduces the tin from 
the hydroehlorate and acetate, provided the iron is made to dip into 
water in which is likewise immersed a bladder containing the tin-solution, 
so that the latter may mix very slowly with the water by endosmose. 
Iron does not precipitate tin from the protochloride at a boiling heat. 
Lead, when first immersed, reduces a small quantity of tin in brilliant 
needles, but the action soon ceases. (Fischer, Pog^. 9, 263; 10, 603.) 
Hydrosulphuric acid gas and hydrosulphate of ammonia precipitate dark- 
brown hydrated protosulphide of tin. This precipitate dissolves in a 
large excess of hydrosulphate of ammonia — provided that compound 
likewise contains hydrosnlphite of ammonia — and is precipitated from 
the solution by acids in the form of yellow bisulphide of tin. (H. Rose.) 
— Hydrosnlphuric acid gives no precipitate in a solution containing less 
than 1 part of tin in 120,000 parts of water. (Pfaff.) — A solution of 
1 part of crystallized hydroehlorate of stannous oxide in 100 parts of 
water, mixed with 15 parts of hydrochloric acid of specific gravity 1*168, 
is immediately precipitated by hydrosulphuric acid; with 25 parts of 
hydrochloric acid, not till after some time; with 40 parts of hydrochloric 
acid, not at all, but immediately on adding more water. (Reinsch. «7. pr^ 
Ckem, 13, 132.) — Iodide of potassium gives a yellowish-white curdy 
precipitate, which, if the tin and iodine are in proper proportion and the 
solution duly concentrated, is soon converted into protiodide of tin. 
Ammonia, carbonate of ammonia, and carbonate of potash throw down 
the white hydrate of stannous oxide, insoluble in excess of these pre- 
cipitants. — An excess of potash, on the contrary, re-dissolves the pre- 
cipitated hydrate, forming a solution, which deposits metallic tin in the 
form of a black powder, slowly in the cold, rapidly when heated, stannate 
of potash being formed and remaining in solution. — Phosphate of soda 
throws down white phosphate of stannous oxide. — Oxalic acid throws 
down white oxalate of stannous oxide. — Croconate of potash gives an 
orange-yellow precipitate with stannous salts. — Succinic acid and the 
alkaline benzoates, according to Pfaff, give white precipitates to the 
ten- thousandth degree of dilution. — Tincture of galls produces, in solu- 
tions not containing a very great excess of acid, an abundance of light- 
yellow flakes. — Ferrocyanide and ferricyanide of potassium produce 
white precipitates soluble in hydrochloric acid. — Stannous salts which 
are insoluble in water, dissolve in hydrochloric acid — ^provided they have 
not been ignited — ^but not in sal-ammoniac, 
c. With Potash and Soda. 

Omdes of Tin, intermedicUe hetwten Stannous and Sicmnic Oxide, 

a. Sesquioxide. Sn'O*. — 1. Aaueous hydroehlorate of stannous oxide, 
somewhat in excess, is boiled with freshly precipitated hydrate of ferric 
oxide or hydrate of manganic oxide, and the precipitated sesquioxide of 
tin thoroughly washed. (Fuchs, Kastn. Arch, 23, 368.) — 

Fe»0» + 2SnCl « Sn=0^ + 2FeCU 



STANNIC OXIDE. 71 

The precipitate is frequentlj mixed with faydrated ferric oxide. (Berzelias.) 
Tlie hydrated ferric oxide, even when recently precipitated, acts much 
less quickly in the cold than at a boiling heat; the dried hydrate requires 
continued boiling; finely pounded specular iron acta but very imper- 
fectly at a boiling heat. £ven when the hydrochlorate of stannous oxide 
contains no free acid, a small quantity of iron is dissolved at the begin- 
ning of the action, before the precipitation of the sesquioxide of tin takes 
place. If the hydrated ferric oxide be briskly boiled with excess of 
stannous hvdrochiorate, the precipitate which forms at first is re-dissolved 
after a while, but appears again on the addition of water; under these 
circumstances, however, the sesquioxide of tin is contaminated with 
bibasic hydrochlorate of stannous oxide. — Pulverixed Pyrolusite acts but 
very slowly, even on boiling; but if the liquid be boiled down nearly to 
dryness, — whereupon a large quantity of hydrochloric acid is evolved, but 
no chlorine— and the residue dissolved in water, sesquioxide of tin sepa- 
rates from the solution, mixed with pyrolnsite. (Fuchs.) — 2. Hydro* 
chlorate of stannous oxide is mixed with hydrochlorate of ferric oxide^ 
4nd as soon as the yellow-colour of the mixture has changed to greenish, 
the hydrated oxide is precipitated from it by adding carbonate of lime in 
excess, and applying a gentle heat. (Fuchs, «/. pr. Chem, 5, 316.)-^ 
3. A solution of hydrochlorate of stannous oxide, saturated as far as 

Cisible with ammonia, is mixed in excess with the dark red solution of 
ic hydrochlorate of ferric oxide, — obtained by saturating aqueous 
hydrochlorate of ferric oxide with recently precipitated hydrate of ferric 
oxide, or by mixing the aqueous solution of the hydrochlorate of ferric 
oxide with as much ammonia as can be added to it without producing a 
permanent precipitate — and the mixture heated to 60^ in a vessel com- 
pletely filled with it. The liquid, which is dark brown at first, gradually 
loses its colour, and the hydrated sesquioxide of tin is precipitated free 
from iron. (Berzelius, Fogg, 28, 443.) — White, with a tinge of yellow. 
(Fuchs.) The precipitate, which is gummy and difficult to wash, dries 
up to a mass of yellow, translucent granules. The hydrate turns black 
when ignited out of contact of air. It dissolves completely in ammonia, 
and is therefore not a mere mixture of stannic and stannous oxides, inas^ 
much as the latter is insoluble in ammonia. (Berxelins.) — [Probably, 
however, it is a salt— SnO,SnO^ containing the soluble modification of 
stannic acid.] 

6. Anomalous Stannaie of Stannout Oxide, — When hydrated stannic 
oxide, obtained by treating tin with nitric acid, is cfigested in cold 
aqueous hydrochlorate of stannous oxide, it abstracts the whole of the 
stannous oxide, and is converted into an orange-yellow compound of 
anomalous stannic acid with stannous oxide. (Fremy, N, J. Pharm, 1, 
344.) According to Fremy's statement, the composition of this substance 
is probably SnO,dSnO'. 

B. Stannic Oxidb. Stannic Acid, SnO'. 

Mnoxide of Tin, Peroxide of Tin, Zinnoxyd, Zinmaure, DeiUoxyde 
dEtain, Oxyde stannique, Acide stannigue. — Found native in the form of 
Tin-stone and Wood-tin, 

Formation. Tin, when heated in the air to its boiling point, bums 
with a bright white flame, and is converted into stannic oxide: Flowers 
of Tin, Zinnblumen, Florcs Stanni s. Jovis. When fused in the air, it 



72 TIN. 

becomes covered ivith a grey film^ and is converted into a grey mixture 
of metallic tin and stannic oxide — Tin-ct^ — which, by longer ignition, is 
converted into pure stannic oxide. — Tin immersed m water containing 
3^ part of potash, becomes dull, and imparts a small quantity of stannic 
oxide to the liquid. (A. Vogel, J. pr. Chem. 14, 107.) — 2. Stannic oxide 
is formed in the decomposition of aqueous vapour by red-hot tin. (Gay- 
Lussac, Reffuault.) — 3. By nitric acid tin is converted rapidly, and with 
violent evolution of heat, into hydrated stannic acid, nitrate of ammonia 
being at the same time produced. Proust states that the oxidation 
of melted tin by fuming nitric acid produces explosion. — 4. With heated 
oil of vitriol tin produces sulphurous acid and stannic sulphate. — 5. The 
deflagration of tin with nitre produces stannate of potash. — 6. When tin 
is heated with mercuric oxide, stannic oxide and metallic mercury are 
formed. — 7. Stannous oxide remains unaltered in dry air at ordinary 
temperatures; in damp air, it is converted, in the course of a year, into 
stannic oxide. (Proust.) When heated in the air, or when merely 
touched by a spark from the flint and steel, it bums like tinder, with 
great rapidity, and produces a small quantity of white smoke. Hydrated 
stannous oxide likewise burns in the flame of a candle, but less rapidly. 
(Berzelius.) — Hydrated stannous oxide placed in contact with carbonate 
of copper under water, liberates carbonic acid and forms a mixture of 
stannic oxide and crystalline laminae of copper. (Proust.) 

Preparation. 1. By rapid or slow combustion of tin. — 2. By preci- 
pitating the hydrate from hydrochlorate of stannic oxide by means of 
ammonia or carbonate of potash, and then washing and igniting. — 
3. By oxidating tin with nitric acid and igniting the hydrate after wash- 
ing. — 4. By heating 1 part of tin-filings in a retort with 4 parts of mer- 
curic oxide. (Berzelius.) 

Properties. Tin-stone belongs to the square prismatic system; Fig. 
21, 29, 30, and other forms. c:c'=133^ 36' 18"; <?:«" = 67° 42' 32". 
Cleavage parallel to e. (Hauy.) — Specific gravity 6*639 (Herapath), 
6*96. (Mohs.) Harder than felspar; transparent, brownish-yellow. Often 
coloured black by ferric and manganic oxide. — ^The oxide prepared by 
method (1) is white; all the other artificial varieties are straw-yellow 
powders which redden litmus, and, when heated, acquire a transient 
orange-yellow and brown tint. Specific gravity of the artificial oxide — 
6'90 (Boullay); of that prepared by (3), 6-64 (Berzelius). Stannic oxide 
in all its forms is very refractory, and not volatile. 

Proust. J. Davy. Thomson. 

Sn 59 .... 78*67 .... 78-1 — 78-4 .... 78-34 .... 78*38 

20 16 .... 21-33 .... 21-9 — 21-6 .... 21-66 .... 21-62 

SnO* .... 75 .... 100-00 .... 1000 — 100*0 .... 10000 .... 100*00 

Gay- Lussac. Berzelius. Klaproth. 

Sn 78-6 .... 78*62 .... 79*5 

20 21-4 .... 20-38 .... 20-5 

Sn02 100-0 Z, 100-00 Z 1000 

Sn02 = 735-29 +2 . 100 = 93529. (Berzelius.) 

Decompositions, By potassium and sodium with the aid of gentle 
heat, stannic oxide is reduced to the metallic state, the reduction being 
attended with incandescence.-^It is also reduced to the metallic state by 



STANNIC OXIDE. 73 

charcoal at a strong red heat (also before the blowpipe on charcoal, if 
carbonate of soda be added and the flame strongly nrged); likewise by 
carbonic oxide gas (Despretz, Ann, Chim. Phys. 43, 222 ; Leplay & 
Laurent, Ann, Chim. Phys, Q5, 404; Gmelin); also by a mixture of equal 
volumes of carbonic oxide and carbonic acid gases (Leplay & Laurent); 
— ^by the oxy-hydrogen blowpipe (Clark, Pfaff), and by a current of 
hydrogen gas at the temperature at which tin decomposes water 
(Despretz); — easily at a low red heat by cyanide of potassium, which is 
thereby converted into cyanate of potash. (Liebig.) — By sulphur it is 
converted into bisulphide of tin, with evolution of sulphurous acid. 

Combinations. Stannic acid exists — aj3 discovered by Berzelius — ^in 
two isomeric states, and, accordingly, forms two series of compounds with 
water, acids, and bases. The hydrate obtained by the action of nitric 
acid upon tin contains the acid aSnO^ which combines with the smaller 
quantity of base, and is, therefore, analogous to metaphosphoric acid : — 
(. The hydrate obtained by precipitating bichloride of tin with an alka- 
line carbonate contains the acid ^SnO^ which saturates three times as 
much base as the former, and is, therefore, analogous to ordinary phos- 
phoric acid. — Berzelius calls the former of these modifications, uxydum 
sfannicum, and the latter Oxydum parastannicum; Fremy distinguishes 
the former as Acide stannique, and the latter as Acide metastannique. It 
would, however, be better to reverse these denominations, so as to make 
them agree with those of the modifications of phosphoric acid.* — For the 
present, the acid obtained by the action of nitric acid upon the metal 
may be distinguished by the epithet Anomalous, — ^ H. Hose is of opinion 
that there exist other modifications of stannic oxide besides those distin- 
guished by Berzelius: in particular, he mentions Tin-stone, and the ignited 
oxide, with which the product obtained by heating stannic oxide to red- 
ness with alkaline carbonates, is probably identical. Rose is moreover 
inclined to regard the diflference between the oxides a and b as due, not 
to any difference of saturating power which they may possess as acids, 
but to some other cause. {Pogg. 75, 1 .) ^ 

a. With Water. — «. Anomalous Hydrate of Stannic Acid. — 
Formed by completely oxidizing tin with moderately strong nitric acid, 
and washing the resulting white powder with water, till the liquid which 
runs through no longer reddens litmus- paper. — It is a white powder, 
which has a density of 4*933, and reddens litmus, even when thoroughly 
washed, although when ignited, it gives off nothing but pure water, 
without any nitric acid or nitrogen gas. (Berzelius.) — The hydrate dries 
up at 55"^ y m the form of colourless, translucent, friable lumps, having a 
conchoidal fracture. When dried at ordinary temperatures, it is white 
and opaque, with a silky lustre, and contains twice as much water as 
when dried at the higher temperature. (Thomson, Ann, Phil, 10, 149.) 













Thomson. 










Berzelius. 


Dried at 55®. 


cSn02 


75 


■ ••• 


89-29 


.•••.•. v«/ .••• 


80-64 


HO 


9 


■ ••• 


10-71 


11 


19-36 



HO,«SnO» 84 .... 10000 100 100-00 

f According to Fremy (N.Ann, Chim. Phys. 23, 393), the anomalous 
hydrate of stannic acid [hydrate of metastannic acid] dried at ordinary 
temperatures in air free from moisture, consists of Sn*0"+10HO; when 

* In Fremy's later memoirs (e.g. N, Ann. Chim. Phys. 23, 393) this change i« 
actually made. 



74 TIN. 

dried in racao, it contains Sn^0^^+5H0; when kept for several hoars at 
130°, it is reduced to Sn'0^'^ + 4H0; and at 160^ it gires off another 
atom of water and becomes Sn^O*° + dHO. The most permanent of theee 
hydrates is that which contains 5U0. [The composition per cent, of 
this hydrate is the same as that of the ordinary hydrate of stannic acid 
dried in vacuo, SnO*,HO.] (Comp. Schaffner, Ann. Fharm. ^Q, 174.) — 
On dissolving any of the above-mentioned hydrates in caustic potash, 
and precipitating by an acid, a precipitate of stannic acid {metastannic 
acid) is obtained, insoluble in nitric acid, but soluble in ammonia. Y 

/3. Ordinary Hydrate of Stannic Acid. 1. By precipitating hydro- 
chlorate of stannic oxide with carbonate of lime, not in excess. The 
washed precipitate reddens litmus. (Fremy, ^. J. Pharm, 1, 342; also 
Pogg. 55, 519), If carbonate of potash is used as the precipitant instead 
of carbonate of lime, the precipitate obtained consists of stannate of 
potash, which, under these circumstances, is insoluble in water. (Fremy.) 
— 2. By precipitating with a caustic alkali and washing thoroughly. 
The gelatinous precipitate resembles pieces of glass when dry; it red- 
dens moistened litmus-paper, and is slightly soluble in water. (Berzelius.) 
— The ordinary hydrate of stannic acid contains more water than the 
anomalous hydrate, and, when boiled in water, or dried for some time in 
vacuo over oil of vitriol at ordinary temperatures, gives off water, and 
is converted into the anomalous hydrate. (Graham, Ann, Pharm, 13, 
146.) According to Fremy, also, this hydrate contains more water than 
the anomalous hydrate, and is converted into the latter by drying at a 
strong heat. [Fremy's later results have already been given, vul. sup,] 

b. With Acids, forming the Salts op Stannic Oxide, or Stannic 
Salts. — The native oxide, and likewise the artificial oxide after ignition, 
are quite incapable of combining with acids. By ignition with excess 
of caustic or carbonated potash or soda, the oxide is rendered solable in 
acids. 

a. Anomalous Stannic Salts. — The anomalous hydrate of stannic acid 
does not dissolve in acids, but takes up some of them, e, g. sulphuric and 
hydrochloric acid, in small quantity. When the compound thus formed 
with sulphuric acid is digested in water, after the excess of acid has been 
removed by decantation, it gives up to the water the acid which it has 
taken up; the hydrochloric acid compound dissolves in water, but is pre- 
cipitated from the solution by acids. (Berzelius.) [vid. Anomalous Hy- 
droclilorate of Stannic Oxide.] — % The solutions obtained in the manner 
just described are decomposed by boiling, the stannic oxide being com- 
pletely precipitated, and the more quickly in proportion as the quantity 
of free acid in the solution is less. — Caustic potash or soda added to the 
solution throws down a white precipitate of the hydrated oxide^ soluble 
in a moderate excess of the re- agent, but re-precipitated on the addition 
of a larger quantity. The precipitate thus formed disappears on the 
addition of water; according to Weber, it contains, when dried at 100^, 
K0,Sn'0"-|-3H0. — Ammonia gives a white precipitate insoluble in 
excess; the addition of tartaric acid does not prevent the precipitation. 
— Carbonate of potash also gives a white precipitate, insoluble in excess. 
— A solution of aSnO*, in the smallest possible quantity of hydrochloric 
acid, gives no precipitate with phosphoric acid, but a copious white pre- 
cipitate, in the course of 12 hours, with arsenic acid, — Nitrate of silver 
gives a white precipitate, from which ammonia dissolves out chloride of 
Mlver and leaves a residue of stannic oxide.— Tincture of galls gives, 



STANNIC SALTS. 75 

after a few hours^ a whitish-yellow precipitate.-^ulpharic acid, added 
to a solution of aSnO* in hydrochloric acid— even if the hydrochloric 
acid is in considerable excess — prodaces a copious precipitate, consisting 
of stannic oxide and sulphuric acid, the latter of which may be extracted 
by water. The precipitate, if heated with hydrochlorate or nitric acid, 
dissolves on the addition of water. The solution, when left to itself for 
a while, deposits a copious precipitate. IT 

p. Ordinary Stannic ScUts, These salts are obtained : 1. By exposing 
stannous salts to the air, or treating them with chlorine, or heating them 
with nitric acid, care being taken not to use too much. Since 1 atom of 
stannous oxide requires but 1 atom of acid to form a normal salt, 
whereas 1 atom of stannic oxide requires 2 atoms of acid (II. 6), it follows 
that if a normal stannous salt is to be converted into a normal stannic 
salt by the action of the air or of nitric acid, it must first be mixed with 
a quantity of acid equal to that which it already contains; in default of 
the requisite quantity of acid, a precipitate is formed during the oxidation, 
consisting either of hydrated stannic oxide or of a basic salt. — 2. By 
dissolving the ordinary hydrate of stannic oxide in acids. — 3. When any 
specimen of stannic oxide, natural or artificial — previously ignited with 
potash, and thereby rendered soluble — is treated with acids [a potash- 
salt is, however, formed at the same time].— Stannic salts are colourless 
or vellowish. Those which are soluble in water redden litmus strongly, 
and have a sour, metallic, and styptic taste. Those which contain a 
volatile acid readily give it off when ignited. Before the blowpipe they 
behave like stannous salts. When boiled with nitric acid, they deposit 
the anomalous hydrate of stannic oxide, or a salt of that base. According 
to H. Rose, the same result is produced on boiling a solution largely 
diluted with water. — Zinc and cadmium immersed in solutions of stannic 
salts, precipitate the tin in the dendritic form. Iron precipitates the 
tin only under the circumstances mentioned under the head of stannotis 
salts; lead ceases to act as soon as it becomes covered with a coating of 
metallic tin. (Fischer.) — Hydrosulphuric acid throws down from these 
solutions, even when they contain excess of acid, a yellow precipitate of 
hydrated bisulphide of tin : the precipitate is formed immediately on 
boiling ; but at ordinary temperatures, and in dilute solutions, it takes 
some time to form. The same precipitate is formed by hydrosulphate of 
ammonia. It is soluble in hydrosulphate of ammonia, caustic ammonia, 
caustic potash, and carbonate of potash ; the solution in caustic potash or 
carbonate of potash deposits hydrated stannic oxide after a while. 
(H. Rose.) — Ammonia throws down a white bulky hydrate, which dissolves, 
with some turbidity, in a very large excess of ammonia; the solution 
becomes clear after standing for some time, but subsequently deposits a 
copious precipitate. (Rose.) The precipitate dissolves readily if the 
solution of the tin-salt is dilute— imperfectly, if it is concentrated. (Gm.) 
Tartaric acid prevents the precipitation by ammonia. (H. Rose.) — Potash 
throws down a white bulky hydrate [containing potash 1], easily soluble 
in a slight excess of the alkali. — Monocarbonate of potash precipitates 
the hydrate [stannate of potash, according to Fremy' with some degree 
of effervescence; the precipitate dissolves in excess of the re-agent, but 
separates again completely after standing for a while. The hydrate pre- 
cipitated by sesquicarbonate of ammonia and bicarbonate of potash does 
not dissolve in excess of those re-agents. (H. Rose.) — Carbonate of baryta, 
strontia, lime, and magnesia precipitate the salts of stannic oxide, even 
in the cold (Demar9ay) ; the hydrate thereby precipitated is free from 



76 TIN. 

alkali. (Fremy.) Phosphate of soda throws down white phosphate of 
stannic oxide. IT. When phosphoric acid (aPO*) is mixed with hydro- 
chlorate of stannic oxide, the mixture solidifies, in the course of a few 
days, to a colourless jelly : arsenious acid gives, after a while, a some- 
what copious precipitate. IT. — Tincture of galls shows no action at first, 
but the mixture, after a while, solidifies in a gelatinous mass. (H. Rose.) 
Succinate of ammonia precipitates stannic salts completely. (Gahn & 
Berzelius.) — Ferrocyanide of potassium produces a white turbidity after 
some time ; subsequently the mixture solidifies to a stiff jelly, insoluble 
in hydrochloric acid : the greater the degree of dilution, the more slowly 
does the solidification take place. (H. Rose.) When hydrochlorate of 
stannic oxide is boiled with acetate of soda or formiate of potash, a pre- 
cipitate is formed, which re-dissolves on cooling, or when washed with 
cold water. (Liebig.) — Phosphuretted hydrogen gas gives no precipitate 
with hydrochlorate of stannic oxide, but colours it yellow. (H. Rose.) 
Iodide of potassium, chloride of gold, oxalic acid, sulphuric, nitric, hydro- 
chloric, and arsenic acid, and ferrocyanide of potassium, give no preci- 
cipitate. %, If the solution be very largely diluted with water, sulphuric 
acid produces a slight precipitate, which, however, is soluble in hydro- 
chloric acid. Nitrate of silver in excess gives a precipitate perfectly 
soluble in ammonia. H. — Those stannic salts which are insoluble in water, 
dissolve — provided they have not been ignited — in hydrochloric acid, but 
not in sal-ammoniac. 

c. With Salifiable Bases, forming salts called Stagnates. 

«. Anomalous StanncUes. By dissolving the anomalous hydrate in 
aqueous alkalis. These salts are composed of 3 At. stannic acid, with 
1 At. metallic oxide, =:MO,3SnO^ and contain water as an essential con- 
stituent, by virtue of which the stannic oxide acquires the character of an 
acid ; hence, when the salts are heated, the stannic oxide is separated in 
the anhydrous state. By ignition with an alkali, the anomalous stannates 
are converted into ordinary stannates. (Fremy.) Acids added to the 
solution of the hydrate in aqueous caustic alkalis, or alkaline carbonates, 
precipitate the hydrate in the anomalous state ; consequently, the preci- 
pitate is not soluble in excess of the acid. (Berzelius.) 

/3. Ordinary Stannates. \. By dissolving the ordinary hydrate of 
stannic acid in aqueous alkalis. — 2. By fusing the anhydrous acid, or 
either of its hydrates, in a silver crucible, with caustic potash or car- 
bonate of potash.— 3. The stannates of the earthy alkalis, earths and 
heavy metallic oxides, are obtained by precipitating the soluble salts of 
these bases with the stannate of potash obtained by either of the preceding 
methods. (Berzelius.) The ordinary stannates contain at most I atom of 
base to 1 atom of acid,=:MO,SnO*. (Moberg, Berz, JaJiresher, 22, 142; 
also J. pr. Chem. 28, 230; Fremy.) The stannates of the fixed alkalis, 
if they do not coutain excess of alkali, are resolved, by ignition, into 
anhydrous stannic acid, and a compound of a small quantity of stannic 
acid with the whole of the alkali. Acids— even carbonic acid^-decom- 
pose them, throwing down the ordinary hydrate of stannic acid. 
(Berzelius.) 

According to Koatner {Katt. Arch, 19, 423) there exists a Stannuretted Hydrogen 
ga9. 

Carbonic acid does not combine with either of the oxides of tin. (Bergman, Proust.) 



TIN AND PHOSPHORUS. 77 



Tin and Boron. 

Borate op Stannous Oxide. — Borax forma with hydrochlorate of 
stannous oxide, a white precipitate which fases to a grey slag. (Wenzel.) 

Tin and Phosphorus. 

A. Phosphide op Tin. — a. Formed by throwing phosphorns upon 
melted tin, or by fusing together equal parts of tin and glacial phosphoric 
acid, whereby phosphate of stannic or stannous oxide is likewise formed. 
(Pelletier, Landgrebe, Schw, 55, 106.) The compound may also be formed 
by heating in a blast-furnace for an hour : 6 parts of tin-filings or 8 of 
stannic oxide with 1 charcoal, 10 bone-ash, 5 pounded quartz, and 5 
boracic acid. (Berthier, j^nn, Chim. Phys, 33, 180.) Silver- white (lead- 
coloured : Berthier), May be cut with the knife ; extends under the 
hammer, but at the same time splits into laminse. Contains from 13 to 
1 4 per cent, of phosphorns, which bums away on the application of heat. 
(Pelletier.) b. When the compound of bichloride of tin with phosphn- 
retted hydrogen is decomposed by water, the phosphuretted hydrogen, as 
it escapes, reduces the bichloriae of tin to the state of protochloride, 
and at the same time precipitates phosphide of tin in the form of a yellow 
powder, which remains for a long time suspended in the liquid, and oxi- 
dizes readily in the air. When washed and dried out of contact of air, 
it exhibits the phosphorus flame before the blowpipe. When ignited in 
hydrogen gas, it gives up its phosphorus, amounting to 55*43 — 56*88 
per cent., and is converted into metallic tin. (H. Rose, Fogg. 24, 326.) 

B. Phosphite op Stannous Oxide, or Stannous Phosphite. — Hy- 
drochlorate of stannous oxide is precipitated by phosphite of ammonia, and 
the white precipitate washed till the wash-water, after boiling with 
nitric acid, no longer gives a turbidity with solution of silver. The salty 
when heated in a retort, blackens without tumefaction, fases without 
glowing, gives off hydrogen rich in phosphorus, and yields a sublimate of 
phosphorus. It is readily oxidized, with formation of a jelly, by warm 
nitric acid, and, on subsequent evaporation and ignition, yields 109*54 
per cent, of stannic phosphate, containing 74*16 stannic oxide and 35*38 
phosphoric acid. Its solution in hydrochloric acid exerts a powerful 
reducing action on several metals. (H. Rose, Pogg. 9, 45.) 











H. Rose. 


2SnO 


134*0 


• t ■■ 


67*54 


66*24 


P03 


55*4 


■ ••• 


27*92 


27*44 


HO 


9*0 


• ••• 


4*54 


6*32 



2SnO,PO' + Aq 198*4 .... 100*00 100*00 

In consequence of the difl&culty of drying the salt, the analysis gave too 
much water. (H. Rose.) 

C. Phosphite op Stannic Oxide, or Stannic Phosphite. — The 
aqueous solution of bichloride of tin gives, with phosphite of ammonia, a 
white precipitate which dries up to a glassy, brittle mass. This, when 
heated, gives off merely water, without any gas, because the binoxide of 
tin is converted into protoxide: hence the residue is soluble in hydrochloric 



78 TIN. 

acid. According to tbis, the precipitate appears to consist of 2SnO^PO'. 
(H. Rose, Pogg. 9, 47.) 

D. Phosphate op Stannous Oxide, or Stannous Phosphate. — Di- 
phosphate of soda added to a solution of protochloride of tin, throws 
down a white powder, insoluble in water and in aqueous sal-ammoniac, 
but soluble in hydrochloric acid: it yitrefies in the fire. 

Tin and Sulphur, 

protosulphide of tin. — stannous sulphide. — sulphostannous 
Acid. — Tin-foil in narrow strips takes fire in sulphur vapour. (Win- 
kelblech.) — The protosulpbide is formed when sulphur is mixed with tin 
heated above its melting point. Since the mass thtis formed still contains 
uncombined tin, it must be pounded and heated w2th fresh sulphur in a 
close vessel. Dark lead-grey; of laminar texture ; crystailizable ; some- 
what tough; not easily pulverized (Berthier); much less fusible than tin. 
By electrolysis, Becquerel obtained sulphide of tin in white cubes 
possessing the metallic lustre. (I. 395.) 

J. Davy, Bergman. 

Berzelius. Pronst. Pelletier. Vauqnelin. 

Sn 59 .... 78-67 .... 78-6 .... 80 .... 85 .... 85*9 

S 16 .... 21-33 .... 21-4 .... 20 .... 15 .... 141 

SqS 75 .... 10000 .... 100-0 .... 100 .... 100 .... 1000 

At a red heat, it slowly converts hydrogen gas into hydrosnlphuric 
acid. (H. Rose.) If the hydrogen be pass^ over it for a longer time, 
nothing but metallic tin remains. (Eisner, J, pr. Chem, 17, 233.) — With 
phosphuretted hydrogen gas at a gentle heat, it is slowly decomposed, 
yielding hydrosulpburic acid, sublimed phosphorus, and a residue of tin. 
(H. Rose, Pogg, 24, 235.) — When fused with cyanide of potassium, it 
yields metallic tin and sulphocyanide of potassium. (Liebig.) — Chlorine 
at ordinary temperatures converts it into liquid bichloride of tin and a 
crystalline compound of that substance with bichloride of sulphur. 
(H. Rose.) 

2SnS + 8Cl = SnCl« + SnC12,2SCP. 

75 parts (1 At.) of stannous sulphide heated to whiteness in a charcoal 
crucible with 53*2 parts (1 At.) of dry carbonate of soda, yield 29*37 
parts (4 At.) of tin and a grey slag containing sulphide of tin, sulphide 
of sodium, and carbonate of soda. With a larger quantity of carbonate of 
soda, the quantity of tin reduced does not exceed three-fourths of the whole. 
Carbonate of soda without charcoal decomposes part of the sulphide of tin at 
a red heat by oxidating the metal. (Berthier, Ann, Chim.Phys, 43, 16.9.) — 
Aqueous hydrochloric acid readily dissolves protosulphide of tin, evolving 
sulphuretted hydrogen and forming hydrochlorate of stannous oxide. 
Potash-ley has no action upon it. (Proust.) — The protosulphide appears 
to be capable of mixing with tin by fusion in all proportions. 

Hydraied Protosulphide of Tin, or Hydrosulphaie of Stannous Oxide, 
— The black-brown precipitate which hydrosulphuric acid or alkaline 
hydrosulphates produce with protochloride of tin, washed with boiling 
water. — Black when dry. — When heated, it gives off water and a small 
quantity of sulphur(?), and is converted into the anhydrous proto- 
sulphide. With hydrochloric acid, it behaves like the anhydrous sul- 
phide. (Pronst.) Not soluble in aqueous sulphurous acid. (Berthier.) 



STANNIC SULPHIDE. 79 

B. SssainsuiPHiBB OF Tin. — By gently igniting an intimate mixtnre 
of 3 parts of stannons sulphide and 1 part of snlphnr in a retort. 100 
parte of stannous sulphide thus treated lake up 10*5 parts of sulphur.^ 
Greyish-yellow, with metallic lustre. — ^When strongly ignited in a close 
Tessel, it gives off one-third of its sulphur. — ^With potash4ey it yields a 
solution of snlphostannate of potassium and stannate of potash, and a 
residue of protosulphide of tin. Concentrated hydrochloric acid conyerts 
it into bisulphide of tin, leaving ^ [^?] of the tin in the form of protoxide. 



2Sn 

3S 


118 
48 


• »•• 


71-08 
28-92 


Berzelios. 
71 
29 








Sn'S* 


166 




10000 


100 



HydraUd Sesquiiulpktde of jTin.— Separates in the form of a liver- 
coloured powder on digesting a saturated solution of sulphostaunate of 
potassinm with bisulphide of tin. By digestion with caustic potash it is 
converted into black protosulphide. (Berzelins.) 

C. BisuLpHiDB OF Tin. — Stannic SuIiPhibe. — SulphostanntcAcib. 
'--Mosaic Gold, A arum mosaicum 9. musivum. — Comp. Woulfe (CrelL Chem, 
J. 1, 149); Bullion {CrelL Ann. 1793, 1, 89); Pelletier {CrelL Ann. 
1797, 1, 46); Proust {N. Gekl. 1, 250). 

Formation. 1. By heating sulphur with protochloride or ammonio- 
protochloride of tin, whereupon one-half of the tin combines with the 
sulphur, and bichloride of tin or chlorostannate of ammonium volatilizes. — 
In the preparation of mosaic gold from tin, sal-ammoniac, and sulphur, 
tho reaction appears to pass through the two following stages: First, 
there is formed, with evolution of hydrogen gas and ammonia, a com- 
pound of protochloride of tin with ssJ-ammoniac {chlorostanniie of ammO" 
nium): 

2Sn + 4(NH»,HCl) = 2(NH3HCl + SnCl) + 2H + 2NH». 

Afterwards, when the temperature rises higher, the sulphur abstracts 
half the tin, while a compound bichloride of tin with sal-ammoniac 
{chlorosiannaie of ammonium) sublimes, together with free sal-ammoniac. 

2(NH«, HCl + SnCl) + 2S -= SnS»+(NH8,HCl + SnCl2) + NH»,HCl. 

If amalgam of tin is used, cionabar likewise sublimes. — 2. By heating 
protoxide [in which case, according to Proust, incandescence is produced I 
or binoxide of tin with silver. — 3. When protosulphide of tin is heated 
with cinnabar, whereupon mercury is set free (Pelletier) [This mode of 
formation is denied by Proust]; — or with corrosive sublimate — whereby 
bichloride of tin and cinnabar are produced at the same time (Woulfe); 
— or with sal-ammoniac and sulphur. — 4. By heating hydrated proto- 
sulphide of tin. 

Preparation, a. Protochloride of tin and sulphur (Proust); — h. Equal 
parts of sifted tin-filings, sulphur, and sal-ammoniac (Pelletier) [Gives a 
less beautiful preparation than e (Woulfe)]; — c. 4 parts of tiu -filings, 3 sulphur, 
2 sal-ammoniac (Woulfe);— -c?. A pulverized amalgam of 2 parts tin and 
2 mercury, with IJ- sulphur and 1 sal-ammoniac (Thenard); — e. A 
pulverizea amalgam of 12 parts tin and 6 mercury, with 7 sulphur and 
6 sal>ammoniac [whereby 1} pt. Tolatile liver of sulphur, 13| sublimed matter, and 
16 parts of fine, and for the most part sublimed, mosaic gold are obtained] (Woulfe). 

— /. A pulverized amalgam of 12 parts tin and 3 mercury with 7 sulphur 



80 TIN. 

and 3 sal-ammoniac; — ^. 2 parts stannous oxide and 1 sulphur (Proust) 
[yields 2*4 mosaic gold]; — h, 8 parts stannic oxide^ 7 sulphur, and 4 sal- 
ammoniac (Woulfe); — i. 10 parts protosulphide of tin, 5 sulphur, and 
4 sal-ammoniac (Woulfe); — h, 5 parts protosulphide of tin, 1 proto- 
chloride, and 2 sulphur (Woulfe); — L 5 parts protosulphide of tin and 
8 corrosive sublimate ^Woulfe) [gives a very beautiful preparation] ; — «i. Hy- 
drated bisulphide of tm [obtained by deflagrating tin with nitre, dissolving the 
stannic oxide in hydrochloric acid, and precipitating with solution of liver of sulphur] 
(Van Mons). 

Either of these mixtures or compounds is heated in a retort or a 
loosely-closed flask placed in the sand-bath, or in an inverted Passau 
crucible, having its mouth closed with a tile and its upturned base 
perforated with an aperture, which is covered with aludels. (Woulfe.) 
A gentle heat is first applied for some hours; afterwards the heat is 
raised, but not quite to redness. — The greater part of the mosaic gold is 
found at the bottom of the vessel — ^the smaller, but purer and finer 
portion, sublimes. 

Properties, — Gold-coloured, translucent, delicate scales or six-sided 
laminaa, unctuous to the touch. Specific gravity 4*425 (P. Boullay); 
4,600 (Karsten). 

J. Davy. Berzelius* 

Sn 59 .... 64-84 636 .... 65 

2S 32 ..., 35-16 36-4 .... .35 

SnS2 91 .... 10000 ~.. 1000 Z 100 

Decompositions. By ignition it is resolved into sulphur and proto- 
sulphide of tin, a portion of the bisulphide, however, subliming at the 
same time in a very beautiful form. If the action of the heat has not 
been long continued, protosulphide of tin is found at the bottom, above 
it a thin layer of sesquisulphide, and undecomposed mosaic gold at the 
top. (Berzelius.) The sulphurous acid gas observed by Proust, and 
previously also by Berzelius, is not evolved unless air has access to the 
heated substance. (Gay-Lussac, Berzelius.) — 2. Boiling aqua-regia con- 
verts it into sulphuric acid and stannic oxide. Hydrochloric acid or 
nitric acid alone has no action on it. — 3. Deliquesces in chlorine gas at 
ordinary temperatures, forming a brown liquid, and afterwards solidifies 
in yellow crystals of SnC1^2SCP. (H. Rose.) — Mosaic gold dissolves in a 
heated solution of potash [also in carbonate of potash, with evolution of 
carbonic acid], forming stannate of potash and sulphostannate of potas- 
sium: 

3SnS« + 3KO = KO,Sn09 + 2(KS,SnS2). 

(For the decomposition by litharge, vid. Lead-oxide,) 

Hydrated Bisulphide of Tin, or Bi-hydrosulphate of Stannic Oxide,-^ 
1. By precipitating hydrochlorate of stannic oxide with sulphuretted 
hydrogen or an alkalme hydrosulphate. — 2. By precipitating aqueous 
sulphostannate of potassium with hydrochloric acid. — Light yellow, 
loosely-coherent flakes, which dry up to dark yellow, hard lumps, having 
a conchoidal fracture. When gently heated, it gives off" water, sulphur, 
and sulphurous acid (?), and is reduced to mosaic gold. (Proust.) At a 
higher temperature, it gives off" the rest of its water with violent decrepi- 
tation, and is at the same time reduced to sesquisulphide by the loss of 
\ At. sulphur; or at a still higher temperature, to protosulphide. (Ber- 



STANNOUS SULPHATE. 81 

celius.) Dissolves in boiling Hydrochloric acid with evolation of sul- 
phnretted hydrogen^ and is thereby converted into hydrochlorate of 
stannic- oxide. (Proost.) 

Bisulphide of tin nnites with the more basic metallic sulphides^ forming 
salts called SulpkostanncUes, These compoands are obtained: 1. By 
dissolving either the anhydrons or the hydrated bisulphide of tin in 
aqueous alkaline hydrosulphates or caustic alkalis. The hydrated 
sulphide dissolves more readily than the anhydrous; with the latter, a 
boiling heat is required, to insure complete saturation. If the alkalino 
hydrosulphates contain 2 atoms of hydrosulphuric acid, 1 atom of the 
latter is expelled with effervescence. When caustic alkalis are used, the 
resulting solution likewise contains stannate of potash, (vid. sup,) — 2. By 
precipitating a heavy metallic salt with aqueous sulphostannate of 
potassium. Those sufphostannates which contain an alkali-metal are not 
decomposed by ignition in close vessels. 

D. Tbtrathionate of Stannous Oxide. — Tetrathionic acid gives a 
white precipitate with hydrochlorate of stannous oxide. (Fordos and 
G^lis.) 

E. ffj/postUphUe of Stannous oxide ? — Aqueons sulphurous acid and 
metallic tin produce protosulphide of tin in the form of a black powder, 
and a solution of stannous hyposulphite, from which acids evolve sul- 
phurous acid and precipitate sulphur. (Fourcroy & Vauquelin.^ Ac- 
cording to Berzelius, and likewise according to Fordos & Gelis, this 
process yields but very little hyposulphite of stannous-oxide, together 
with the sulphide, but on the other hand, a large quantity of sulphite,— 
the tin, in fact, behaving exactly like cadmium under similar circum- 
stances (p. 57). 

F. Sulphite op Stannous Oxide, or Stannous Sulphite.— Sulphite 
of ammonia added to hydrochlorate of stannous oxide throws down, at 
ordinary temperatures, the greater part, and at a boiling heat> the whole 
of the stannous oxide, in the form of a white basic salt. This salt 
gradually ffives up all its acid to boiling water, and is converted into pale 
yellow, anhydrous protoxide of tin. (Berthier, JV. Ann. Chim. Phys. 7, 
81; Comp. Bottinger, Ann. Fharm, 51, 408.) 

IT G. Stannous Hyposulphate. — Known only in solution. When 
concentrated in vacuo, it deposits protosulphide of tin. (Bouquet.) IT 

H. Sulphate op Stannous Oxide, or Stannous Sulphate.— 
a. Biuic. — Precipitated on mixing h with an alkali. (A. BerthoUet.) 

6. Monosulpkate, — 1. Protosulphide of tin heated with red oxide of 
mercury yields the anhydrous salt, which bears a dull red heat without 
decomposition.<^2. By heating tin in oil ofvitriol slightly diluted. —-3. By 
dissolving hydrated stannous oxide in sulphuric acid.-~-4. Sulphuric acid 
added to solution of hydrochlorate of stannous oxide throws down a white 
powder. The liquid obtained by (3), and the solution of the saline 
mass (1), (2), or of the white powder (4), all yield needles on cooling. 
(A . Berthollet.) At a red heat the salt is resolved into sulphurous acio^ 
oxygen gas, and stannic oxide. (Gay-Lussac.) When ignited in hydrogen 
gas, it leaves metallic tin with a small quantity of sulphide. (Arfvedson, 
Pogg. 1, 74.) IT According to Bouquet {N. /. Pharm. 11, 459), the salt 
TOL. y. o 



82 TIN. 

SnO, SO* ciystallizea in larainffi from a hot saiaratecl solution of recently: 
precipitated stannous oxide in dilute sulphuric acid. It is veiy soluble 
in water; the solution soon becomes turbid from deposition of a basic 
salt, but its transparency is restored by adding a few drops of sulphuric 
acid. When ignited it leaves stannic oxide. Combines with the 
sulphates of potash and ammonia^ forming crystallizable compounds. IT 



I. Sulphate op Stankio Oxidb, or Stannic Sulphate. — a. Ordi- 
nary, 1. By dissolving ordinary hydrate of stannic oxide in aqueous 
sulphuric acid. — 2. By heating tin with excess of oil of vitriol, where- 
upon sulphurous acid and sulphur are given off, and stannic sidphate 
remains behind. Kraskowitz {Pogg. 35, 518) heats 1 part of granulated 
tin with 3 parts of oil of vitriol in a capacious iron vessel; whereupon 
slight effervescence is at first produced, with formation of a white scum; 
then suddenly great heat is developed, and sulphurous acid mixed with 
sulphur vapour is given off; the vessel should therefore be cooled to 
prevent frothing over. After the frothing has ceased, the excess of oil of 
vitriol is driven off by the application of a stronger heat, which is con- 
tinued till the residue becomes friable, and thereby separable from the 
metallic tin mixed with it. The aqueous solution (1) yields no precipi- 
tate on boiling. (Berzelius.) 

6. AnomalmtB, The oxide of tin produced by the action of nitric 
acid does not dissolve in sulphuric acid either concentrated or dilute; a 
portion of the acid is, however, absorbed by it, with tnme&ction^ and may 
be extracted by water. (Berzelius.) 

K. SULPHOCARBONATB OF STANNOtTS SuLPHIDE, and SuLPHOCAR- 

BONATE OP Stannic Sulphide. — Aqueous sulphocarbonate of calcium 
gives a dark brown precipitate with stannous salts and brownish-yellow 
with stannic salts, (berzelius.) 



Tin and Selenium. 



A. Selenide op Tin. — a. Tin combines with selenium, on the appli- 
cation of heat, forming a grey, metallic, shining substance, which, when 
heated in the air, is readily decomposed without fusion, yielding selenium 
which volatilizes, and stannic oxide which remains behind. — h. Biselenide 
of Tin may be obtained by precipitating hydrochlorate of stannic oxide 
with hydroselenic acid. 

B. Selenite op Stannic Oxidb. — White powder, insoluble in water, 
but soluble in hydrochloric acid, and precipitated from the solution on 
the addition of water. When heated, it first gives off water, and then 
the whole of its acid. (Berzelius.) Formula of the dry salt, SnO*, 2SeO\ 
(Muspratt.) 

Tin and Iodine. 

A. Protiodide op Tin, or Stannous loDiim.'^Todostannous AM. 
1. When tin-filings are heated with a twofold quantity of iodine, a 
brown-red, translucent compound is formed, which yields a dingy orange- 
yellow powder, and fuses very easily (according to Sir H. Davy, it 
volatilizes when heated more strongly); the combination is attended with 



TIN AND IODINE. 83 

noue and ignitioD. (Oay-Lassac, RammelBberg, ^ogg^ 48, 169.) IT Ac- 
cording to Henry (^hu. Traru, 1845, 363), tin heated with twice its 
weight of iodine, yields two componnds, the protiodide SnI, and the 
bin iodide SnI', which may be separated by sublimation, the latter 
volatilizing at 180° C. while the former remains fixed at a red heat. IT 
2. A dilate solation of protochloride of tin mixed with a yeir slight 
excess of iodide of potassium soon deposits a large quantity of yellowish* 
x^ crystalline tufts. If the mixture was warm, the iodide of tin is 
deposited, on cooling, in fine yellowish-red needles. (BouUay, ^nn. Chinu 
Phys, 34, 372.) Gay-Lussac likewise obtained orange-yellow silky 
crystals, by treating the iodide of tin (1) with a small quantity of water, 
and pouring off the liquid from the separated hydrate of stannous oxide— 
that liquid containing stannous oxide with excess of hydriodic acid. 
According to Gay-Lussac, these crystals consist of acid hydriodate of 
stannous oxide, but, according to Boullay's analysis, they are formed of 
protiodide of tin. 

Protiodide of tin, when heated in the air in contact with stannic 
oxide, leayes a substance, which, when treated with water, is resolved 
into stannic oxide and hydriodic acid which dissolves. (Boullay.) The 
iodide prepared by ^1) is easily decomposed by water— especially with the 
aid of heat, and tne more completely in proportion as the quantity of 
water is greater — ^yielding hydrated stannous oxide which is precipitated, 
and aqueous hydriodic acid containing a trace of tin. (Gay-Lussac, 
Bammelsberg.) H Dissolves in water sparingly, but without decompo- 
sition; fuses readily and forms a dark-red mass, having a crystalline 
texture; yields a powder of a red colour and considerable lustre, like red 
lead. (Henry.) IT The iodide (2) dissolves in water without decomposi- 
tion, and more abundantly in warm than in cold water; it is like'* 
wise soluble in hydrochlorate of stannous oxide. Hence it is not precis 
pitated from a solution of that compound by small quantities of iodide of 
potassium. (Boullay.) Iodide of tin combines with the more baao 
metallic iodides. (Boullay.) 

Boullay (2.) 

Sa 59 .... 31-89 ........ 32-01 

1 126 .... 68-11 67-99 

SnI ^ 185 Z 100-00 ZZ 100*00 

When tin is heated in excess with iodine and a large quantity of 
water, violent action ensues, the tin is rapidly oxidated, and a solution of 
hydriodic acid is formed, containing but a trace of tin. (Gay-Lussac.) 

On dissolving in aqueous iodide of potassium half as much iodine as 
it already contains, and adding protochloride of tin to the solution, the 
colourless mixture yields no precipitate, but on evaporation deposits a 
yellow powder, slightly soluble in water, probably Sn'I'. (Boullay.) 

IT B. BiNioDiBE OP Tin. — SnP. — 1. Separated by sublimation from 
the mixture of protiodide and biniodide obtained by heating tin with 
twice its weight of iodine («ttpra).— -2. By boiling equal parts of proto* 
chloride of tin and iodine with a small quantity of water. By (1); 
orange-yellow, shining crystals; by (2^: red crystals. Sublimes at 180°. 
Easily decomposed by water. (Henry.) IT 

C and D. Stannotts and Stannic Iobates. — Iodic acid and iodate of 
potash give white predpitates both with hydrochlorate of stannous oxide 

g2 



84 TIN. 

and with hydrochlorate of stannic oxide. (Pleisclil.) When hydrochlorate 
of stannous oxide is dropped into iodate of soda, iodate of stannons oxide 
is precipitated, white at first, but taming brown in a few minutes, and 
then grey, from liberation of iodine and formation of stannic hydro- 
chlorate. If, on the contrary, the iodate of soda be added to the stannous 
hydrochlorate, the white precipitate which forms at first is quickly 
le-dissolved, and the solution acquires a yellow colour; with a larger 
quantity of iodate of soda, a separation of iodine takes place. (Rammels- 
berg, Pogg. 44, 567.) 

Tin and Bromine. 

A. Protobromide op Tin, or Stannous Bromide. — Bromostantwtu 
Acid. — Formed by heating tin in hydrobromic acid gas (Balard), or with 
protobromide of mercury (L5wig). — Greyish- white, with considerable 
lustre; when heated, it fuses to a yellowish oil. — When heated in the air 
or in contact with nitre, it gives off bibromide of tin and leaves the 
binoxide. 

Aqueous Protobromide of Tin, or Hydrchromate of Stannous Oxide.-^ 
1. By dissolving stannous bromide in water.*-2. Tin dissolves in aqueous 
hydrobromic acid with evolution of hydrogen, very slowly when the 
liquid is cold, more quickly when it is raised to the boiling point. — The 
colourless solution, which reddens litmus, becomes gelatinous when 
evaporated, but does not crystallize; when more strongly heated, it 
gives off hydrobromic acid. (Lowig.) 

B. Bibromide of Tin, or Stannic BROMiDE.-^^romoxtonntc Acid, — 
Tin takes fire in contact with bromine and is converted into stannic 
bromide. (Balard.^^2. Protobromide of tin with bromine yields the same 
compound. (Lowig.) — White, crystalline, easily fusible and volatile; 
gives off a faint white cloud when exposed to the air. In heated oil of 
vitriol, it fuses, without visible decomposition, into oily drops. With 
nitric acid, after a few seconds, it gives off bright-coloured vapours of 
bromine. Dissolves in water without apparent decomposition. (Balard.) 

Bromine-water converts stannons oxide, with evolution of heat, into 
mono-hydrobromate of stannic oxide; on stannic oxide, bromine exerts no 
action. (Balard.) 

C. Bromate op Stannous Oxide, or Stannous Bromate.— Bromate 
of potash gives a yellowish- white precipitate with hydrochlorate of stan- 
nous oxide. (Simon, Repert, 65, 207.) 

D. Bromate op Stannic Oxide, or Stannic Bromate.— Aqueous 
oroniic acid dissolves but a small quantity of the ordinary hydrate of 
stannic acid, even after digestion for weeks. The hydrate separated from 
the liquid becomes translucent and glassy when dried over oil and vitriol, 
and loses 18 per cent, when heated to 180^. (Rammelsberg, Pogg. 
55, 87.) 

Tin and Chlorine. 

Protochloride op Tin, or Stannous Chloride. — CJdorostannous 
Acid. — Butter of Tin. — 1. By gradually heating tin or amalgam of tin with 
calomel, or with at most two parts of corrosive sublimate, the mercnry 



STANNOUS CHLORIDE. .85 

volatilizing. — 2. By heating tin in hydrochloric acid gas, hydrogen being 
set free. — 3. By heating hydrochlorate of stannous oxide in close vessels 
— whereupon, when the heat is gradually raised to redness and the 
receiver changed, the chloride of tin passes over after the water. Capi- 
taine {J, Pharm, 25, 552) gently heats commercial tin-salt in a capacious 
crucible (to prevent frothing over) as long as it froths up and gives off 
water and sulphuric acid — ^pours the mass, as soon as it is brought to a 
state of tranquil fusion, into a small crucible — ^then pounds it up coarsely, 
and distils it from a coated glass retort. ' The first portions of stannous 
chloride which pass over are perfectly pure; the last portions contain 
a small quantity of iron, from which they may be freed by a second 
distillation. 

Translucent, almost pure white (frequently grey), with a fatty lustre 
and conchoidal fracture. Fuses at 250° to an oily liquid which pene* 
trates the crucibles and makes them crack; boils at a heat near redness, 
but always with some decree of decomposition. (J. Davy, Schw. 10, 821; 
Capitaine.) When cooled after fusion, it remains liquid for a long time^ 
but afterwards becomes syrupy and solidifies. (Marx.) 

J. Davy. 

Sn 59*0 .... 62-5 ........ 62-22 

CI 35-4 .... 37-5 37-78 

BnCl 9^4 .... 100-0 ZZ 10000 

When heated to bright redness, it gives off bichloride of tin and 
afterwards unaltered protochloride, leaving a black shining mass which 
dissolves in aqueous hydrochloric acid with evolution of hydrogen gas, 
and forms a solution of stannous hydrochlorate. (A. Vogel, Schw, 21, 6Q.) 
When heated to the boiling point, it passes over in company with bichlo- 
ride of tin, and leaves yellow, earthy stannous oxychloride, SnCl, 
SnO. (Capitaine.) — When heated with sulphur, it yields bichloride and 
bisulphide of tin. (Proust.) 

2SnCl + 2S= SnC12 + SnS^. 

When heated in the air, or with nitre, chlorate of potash, or mercuric 
oxide, it gives off bichloride of tin and leaves binoxide. — At ordinary 
temperatures, it does not suffer much alteration by exposure to the air; 
in the course of three weeks, however, it becomes somewhat disintegrated, 
but still dissolves completely in water. 

HydrcUed and Aqueotis Protochloride of Tin, or Crystallized and 
Aqueotu Mono-hydrochlorate of Stannotts Oxide. — Tin-salt. — 1. Proto- 
chloride of tin dissolves without turbidity in water [freed from air?]. 
(Capitaine.) The solution is commonly turbid, partly perhaps from the 
presence of air in the water, partly because the chloride of tin may have 
been mixed with oxychloride. — 2. Tin dissolves very slowly in cold, 
more quickly in warm hydrochloric acid, and with evolution of hydrogen 
gas. The preparation on the large scale is performed in copper vessels, 
which, so long as any portion of tin remains undissolved, are not attacked 
by the add.— 3. If granulated tin be covered with hydrochloric acid, 
then the acid poured off, and the tin exposed to the air — afterwards the 
acid poured on again, and so on alternately — the tin takes up oxygen 
from the air, whereby it becomes heated, and dissolves much more 
quickly than by the simple action of the acid. (Berard.) — IT 4. In the 

E reparation of Tin -salt on the large scale, NoUner recommends that the 
ydroohloric acid, as it is evolyed from the jetoits, be made to act 



86 TIN. 

directly npon granulated tin contained in stone-ware receirers adapted to 
the retorts, and that the concentrated solation of tin-salt thus formed be 
afterwards evaporated in tinned pans with the addition of granulated 
tin. {Arch. Pharm, 6S, 120.) — IT The solution, when eyaporated and cooled, 
yields large, transparent, and colourless prisms (and octohedrons: Dumas), 
haviug a disagreeable metallic taste. According to Berzelius, their com- 
position is SnCl,HO; according to Henry, they contain 2 atoms of water, 
SnCl,2H0. The crystals when heated evolve water and hydrochloric 
acid containing a small quantity of tin, and leave protochloride and prot- 
oxide of tin. Cold oil of vitriol separates from them but a small quan- 
tity of hydrochloric acid; heated oil of vitriol separates hydrochloric 
acid — ^together with small quantities of stannous chloride, sulphurous 
acid, and sulphuretted hydrogen [the two latter substances partly decom- 
posing each other and yielding a precipitate of sulphur] — and forms 
stannic sulphate. (A. Vogel.) 

The crystals generally give a turbid solution with water, which, 
however, may be rendered transparent by the addition of hydrochloric 
acid [partly, perhaps, because the crystals have become oxidated by 
exposure to the air, partly because the air contains water]. The turbidity 
of the solution increases with excess of water, and diminishes with 
excess of the tin-salt. (Fischer.) — The solution absorbs oxygen from 
the air, and if it does not contain an excess of hydrochloric acid, becomes 
turbid, from formation of bi-hydrochlorate of stannic oxide and precipita* 
tion of stannous oxychloride. Probably in this manner: 

3(SnO, HCl) + O « SaO*, 2HCI + SnCl, SnO + HO. 

By longer exposure to the air, the solution recovers its transparency and 
acquires a yellow colour — the change being slower as the solution is more 
concentrated. (Fischer, Kastn, Arok, 13, 225; Capitaine.) [Does there 
exist a mono-hydrochlorate of stannic oxide, which forms a yellow solution 
in water]] — The solution of stannous hydrochlorate mixed with sulphurous 
acid, becomes yellow and turbid, especially when warmed, and yields a 
deep-yellow precipitate of hydrated bisulphide of tin, the odour of sul- 
phurous acid being at the same time destroyed, and hydrochlorate of 
stannic oxide form^. (Hering, Ann, Fharm, 29, 90.) Probably thus : 

6SnO + 2S0» = 5SnO» + SnS^ 

The stannic oxide formed remains dissolved in the excess of hydrochloric 
acid. — According to Girardin (Ann. Chim. Phys. 61, 286), if the hydro- 
chloric acid contains even a small quantity of sulphurous acid, the solution 
of the tin-salt in it is attended with the formation of a yellow cloudiness; 
and if water be afterwards added, a fiftint smell of sulphuretted hydrogen 
Iq evolved and a yellowish-brown precipitate formed, which is a mixture 
of stannic sulphide and stannic oxide. — Trithionic acid added to the heated 
tin-solution throws down sulphide of tin. (Persoz.) — The solution reduces 
hypochlorous acid, evolving chlorine and being itself converted into a 
stannic salt. (Balard.) It likewise reduces nitric acid to nitric oxide, 
and this again, by longer contact, to nitrous oxide; — tungstic acid, even 
when united with an alkali, to blue oxide of tungsten; — ^molybdic acid 
to blue oxide of molybdenum ;«-chromio acid to chromic oxide; — ^man- 
ganic acid to manganous oxide; — ^hydrated peroxide of manganese, on 
boiling, to manganous oxide, with precipitation of sesquioxide of tin 
(Fuchs); — arsenic acid to arsenious acid, and this, by longer digestion, to 
metaUlo arsenic (Woulfe^ Greli* Ohem, J, 1, 155);-^ftatimonious aoid to 



STANNIC CHLORIDE. 



87 



antimony (Wonlfe); — ^mononitrate of bismuth-oxide to black suboxide 
(A. Vogel) ; — the red and brown peroxides of lead to chloride of lead 
(A. Vogel); — ferric salts to ferrous salts (with formation of hydrochlorate 
of sesquioxide-of-tin, (Fuchs, comp, p. 80); — cupric oxide and its salts to 
dicfaloride of copper; — the protoxide^ dichloride, protochloride, and 
oyauide of mercury to metallio mercury (A. Vogel, Kastn, Arch, 23, 78); 
— HBilver-salts to metallic silver; — ^with gold-s^ts, the stannous solution 
forms a precipitate which is brown or purple according to circumstances. 
*— Copper immersed in the stannous solution mixed with a large quantity 
of hydrochloric acid, throws down metallio tin in the form of a greyish- 
black powder^ only however wJien the solution is exposed to the air and 
boiled. (Reinsch, J. pr. Ghem, 24, 248.) 

Protochloride of tin unites with the chlorides of the alkali-metals, 
forming salts which may be called Ohlorostannites. — According to Kuhl* 
mann, it forms definite compounds with nitrous, hyponitric, and nitric 
acid. It is easily soluble in absolute alcohol. (Capitaine.) 

B. Htdrated Stannous Oxychloridb, or Di-htdrochlorate op 
Stannous Oxide. — By precipitating hydrochlorate of stannous oxide 
with an insufficient quantity of potash. — White powder. (Proust.) — At 
a red heat, it yields water containing hydrochloric acid and hydrochlorate 
of stannous oxide, a sublimate of protochloride of tin and a residue of 
stannous oxide. — Froths up yiolently with strong nitric acid; gives off 
hydrochloric acid gas when treated with oil of vitriol; and dissolves 
without effervescence in hydrochloric acid, acetic acid, and dilute nitric 
or sulphuric acid, forming stannous salts. (J. Davy, Schw. 10, 325.) 

Or : J. Dayy. 

SnCl 94-4 .... 5011 2SiiO 134-0 .... 71-13 .... 704 

8nO 67-0 .... 35-56 HCl.... 36-4 .... 19-32 

3H0 27-0 .... 14-33 2H0 180 .... 955 

SnCl, SnO + 3Aq. 188-4 .... 100*00 188-4 .... 100-00 

0. Aqueous Ses(iuichloridb of Tin, or Htdrochloratb of 
Sesquioxidb-of-tin. — Hydrated sesquioxide of tin dissolves readily in 
hydrochloric acid. (Fuchs.) It dissolves with difficulty in cold dilute 
hydrochloric acid^ and the concentrated acid does not become saturated 
with it till after long digestion, which, to prevent oxidation, must be 
performed in close vessels. The solution has a purely astringent taste, 
yields, with hydrosnlphurio acid, a lighter brown precipitate than the 
stannous-salt, and a remarkably fine purple with gold-salts. (Fuchs.) 

D. Bichloride of Tin, or Stannic Chloride. — Chlorostannic Acid. 
^^Fuming Spirit of Lihavitts, Spiriiua fumans Libavii. 

Formation. 1. Tin-foil takes fire after a while in chlorine gas, and burns 
with emission of red sparks, forming bichloride of tin. — 2. Protochloride 
of tin likewise takes fire in chlorine gas at ordinary temperatures. — 
3. Tin heated with protochloride of mercury volatilizes in the form of 
bichloride. 4. Protosulphide of tin heated with sulphur or with oxidized 
bodies is converted into bisulphide. 

Preparation. 1. When dry chlorine gas is slowly passed through 
the retort d, App. 52, containing tin-foil or melted tin, the bichloride 
distils over into the receiver f, which must be kept cool. — 2. By distilling 
1 part of tin with 5 parts of protochloride of mercury*-^* By distilling 



88 TIN. 

conoentrated hydrocblorate of stannic oxide with famine oil of yitrioL 
(J. Dayy.) — 4. By distilling common salt with stannic siuphate : 

2NaCl + SnO»,2SO» = 2(NaO,SO») + SnCP. 

The stannic sulphate prepared hy method 2, page 82, is pounded in a 
mortar while still warm — then sifted — ^intimately mixed with an equal 
weight of common salt — and heated in an iron retort with glass receiyer 
(or in a glass retort — in which, however, it is difficult to effect complete 
decomposition) — the heat being gradually raised as long as anything 
f>asses over. The bichloride of tin which distils over — ^together with 
hydrochloric acid gas — contains chloride of iron and crystab of hydrated 
bichloride of tin. To free it from iron and water, it is rectified in a 
glass retort with from twice to four times its weight of oil of vitriol. 
(Von Kraskowitz, Fogg. 35, 518.) 

Properties. Thin, colourless liquid, which does not freeze at ^29% 
boils at 120° under a pressure of 0*767 met., and yields a vapour whose 
density is 91997 (Dumas); gives off white fumes m the air at ordinary 
temperatures. 

!* Berzeliiui. J. Dayy. 

Sn 590 .... 45-45 .... 54*43 .... 42*1 

2C1 70-8 .... 54-55 .... 45*57 .... 57*9 

SnCP 129*9 .... 100*00 Z lOOsOO Z 100*0 

Vol. Sp. gr. 

Tin vapour 1 4*0905 

Chlorine gaa 2 4*9086 



Vapour of SnCP 1 8*9991 

Decomposed by sulphuretted hydrogen with the aid of heat, the 
products being hydrochloric acid gas and bisulphide of tin. (H. Bose^ 
Fogg. 24, 339.) 

SiiCP + 2HS = SnS2 + 2HC]. 

When heated with nitric acid, it gives off chlorine and nitric oxide, and 
deposits stannic oxide. (Gay-Lussac.) To mercury it slowly gives up 
chlorine, so that calomel ana stannous chloride are produced. (Dumas.) — 
Alcohol decomposes it, with formation of hydrochloric ether and deposi- 
tion of stannous oxychloride. With oil of turpentine it becomes strongly 
heated, the turpentine sometimes taking fire, and deposits stannic oxide. 
(J. Davy.) Not decomposed by defiant gas. (Wohler.) 

Hydrated Bichloride of Tin, or Crystallized Hydrochloraie of Stannic 
Oxide, — 22 parts of bichloride of tin solidify with 7 parts of wat^r, 
forming a colourless mass of crystals fusible by heat. (Adet.) — IT If this 
crystalline mass be treated with an additional quantity of water, and the 
liquid gently evaporated, deliquescent crystals are obtained, which appear 
to contain 5 atoms of water: SnCl',5H0. When dried over sulphuric 
acid, they give off 3 At. water, and are converted into SnGP,2H0. 
(Lewy, Compt. rend. 21, 369.) IT 

Aqueotis Bichloride of Tin, or Aqueous HydrochloraJte of Stannic 
Oxide. — a. Ordinary. — Colour-makers' Composition, — 1. By dissolving 
bichloride of tin in water. — 2. By saturating an aqueous solution of 
stannous chloride with chlorine gas. — 3. By mixing the same solution 
with a quantity of hydrochloric acid twice as great as that which it 
already contains, and exposing it to the air for some time,— -or by heating 



CHLOROSTANNATE OP PHOSPHURETTED HYDROGEN. 89 

it with nitric acid not in excess. — 4. By dissolying tin in aqua-regia not 
containing too much nitric acid. A mixture of nitric acid with sal- 
ammoniac or common salt, or of hydrochloric acid with nitre may 
likewise be used. — The solution obtained by the agency of nitric acid 
always retains a portion of that acid, and therefore deposits anomalous 
hydrate of stannic oxide when boiled (BoUey, Ann, Fharm. 39, 103); 
according to H. Rose, this effect is not produced till the solution has 
attained a somewhat high degree of concentration. — The compound may 
likewise be obtained by dissolnng ordinary hydrate of stannic oxide in 
hydrochloric acid. The anomalous hydrate of stannic oxide, when dis- 
tilled with hydrochloric acid, is partly conyerted into ordinary hydro- 
chlorate of stannic oxide, which passes oyer, while the rest remains 
behind, as anomalous hydrochlorate of stannic oxide, in the form of a 
yellow mass, which, when digested in water, partly dissolyes and partly 
swells up. (Berzelius.) — Colourless liquid, not decomposible by boiling; 
yields crystals when evaporated and cooled. 

b. Anomalous. — The hydrate of stannic oxide produced by the action 
of nitric acid does not dissolye in hydrochloric acid eyen when boiling 
and concentrated, but takes up a portion of that acid and acquires a 
yellowish tint, and is thereby conyerted— after the excess of acid has 
been poured off, and the residue dried on bibulous paper — ^into a soft 
yellow mass perfectly soluble in water. Nevertheless, the resulting 
solution, even when largely diluted, coagulates at a boiling heat, and if 
concentrated becomes as thick as white of egg. It likewise yields a 
precipitate when mixed with concentrated hydrochloric acid, — but the 
precipitate dissolves again in water, after the acid is poured off. When 
this compound is distilled, aqueous hydrochloric acid passes over firsts 
then hydrochloric acid gas, with a small quantity of stannic chloride, 
while anhydrous stannic oxide is left behind. (Berzelius.) — Ammonia or 
potash added to the aqueous solution yields a white precipitate slightly 
soluble in excess of the alkali. (H. Rose.) 

E. and F. — Bichloride of tin dissolyes sulphur and phosphorus, 
forming oily liquids. 

G. Chlorostannate op Phosphuretted Hydrogen. — Bichloride of 
tin absorbs both the more inflammable and the less inflammable phos- 
phuretted hydrogen gas without decomposition, thereby acquiring a 
yellow colour, ana being subsequently converted into a yellow solid body 
which fumes in the air and absorbs moisture with avidity. When heated 
out of contact of air, it gives off hydrochloric acid gas with a sublimate 
of phosphorus^ and leaves protochloride of tin: 

PH»,3SiiCl« = 3Sna + 3HCl + P. 

Ammoniacal gas colours the compound black, even iji the cold, and 
appears to form ammonio-bichloride of tin together with several other 
products. — Water added to this compound gives off non-spontaneously 
inflammable phosphuretted hydrogen gas with effervescence, and forms 
hydrochlorate of stannous and of stannic oxide, together with a precipitate 
of terphosphide of tin (p. 88). Aqueous solution of potash, carbonate of 
ammonia, or carbonate of potash, and hydrochloric acid likewise give 
rise to the evolution of the less inflammable yariety of phosphuretted 
hydrogen; but aqueous ammonia evolves the spontaneously inflammable 
gas. (H. Rose, Fogg. 24, 1 59.) 



00 TIN. 

H. Roie« 

PH» 34-4 .... 812 , 8-64 

38nCl» 389-4 .... 91*88 91-36 

FH»,3SiiCl* .... 423-8 .... 100*00 ~. 100*00 
H.— Bichloride of tin may be mixed with terchloride of phosphorus. 

I. Chlorosulphidb of Tin.— -SnS^2SiiCl'. — Sulphuretted hydrogen 
is rapidly absorbed by bichloride of tiu^ with formation of hydrochlorio 
acid gas: 

3S&C1S + 2HS = SnS<,2SnCl3 -f 2HC1. 

The liquid obtained by perfect saturation with sulphuretted hydrogen is 
transparent, of a yellowish or reddish colour, and heayier than water. 
When heated, it leaves bisulphide of tin, while the bichloride volatilizes. 
Water added to the liquid dissolves out the latter compound and throws 
down 25*07 per cent, of bisulphide of tin. (Dumas, «7. Chim. MH. 8, 478; 
also Schw. Q^y 409.) 

K. Chloridb of Sulphur and Tin.— Produced by the action of 
chlorine gas on bisulphide of tin at ordinary temperatures : 

SnS» + 6C1 = SnCP + 2SCP. 

A bulb is blown on a fflass tube and filled with mosaic gold; a cylindrical 
enlargement is also blown on the tube, the end drawn out, and passed 
into a chloride of calcium tube, to keep out the moisture of the air. As 
soon as the dried chlorine gas passed into the bulb has decomposed the 
mosaic gold, the bulb is gently heated till the compound sublimes into 
the cylindrical enlargement; air is passed over it to drive out the excess 
of chlorine ; and the cylinder sealed at both ends. Protosnlphide of tin 
likewise yields this compound, mixed however with free bichloride 
(p. 78). 

Large yellow crystals, which fuse when heated, and sublime without 
decomposition; they fume in the air more strongly than bichloride of 
tin. — The crystals dissolve gradually but completely in dilute nitric acid, 
with evolution of nitrous fumes; the solution contains stannic oxide, 
together with the whole of the sulphur in the form of sulphuric acid. 
With fuminff nitric acid they form a thick white mass, perfectly soluble 
in water.-^ W ith water they form a solution which is milky from sepa- 
rated sulphur, but does not smell of sulphurous acid. The solution when 
boiled yields a deposit of stannic oxide soluble in hydrochloric acid; with 
hydrosulphuric acid it forms bisulphide of tin, and the filtered liquid 
treated with chloride of barium yields sulphate of baryta. With nitrate 
of silver-oxide, it yields a white curdy precipitate, which contains hypo- 
sulphite of silver-oxide, together with chloride of silver, and therefore 
turns black. Hence it appears that the aqueous solution contains 
bichloride of tin, sulphuric acid, hyposulphurous acid, and hydrochlorio 
acid. [But whence the precipitation of stannic oxide on boiling?]— 
Aqueous ammonia separates sulphur and part of the stannic oxide from 
the crystals, but takes up a large proportion of the stannic oxide, together 
with hyposulphurous, sulphuric, and hydrochloric acid. — The crystals 
absorb ammoniacal gas with great evolution of heat, and are converted 
into a yellowish- brown mass; and when this mass is digested in water, 
the whole of the stannic oxide is left undissolyed together with sulphur 



lODOCHLORIDE OF TIN. 91 

in the form of white flak'es. The filtrate, which is neutral at first, acquires 
after a while, the property of reddening litmus, and contains hyposulphite^ 
sulphate^ and hydrochlorate of ammonia. (H. Rose, Fogg, 42, 517.) 



8n 




•••• 
•••• 


19-44 
10-55 
70-01 


H.Rose. 


6C1 


32-0 

212-4 


11-38 
68-19 









BiiCl*,2Sa« 303-4 .... 100-00 99*39 

Bichloride of tin majy likewise be mixed with diohloride of sulphur, 
and forms crystals with u in the cold. (H. Rose, Fogg. 16, 67.) 

I. Sulphate of Stannic Chlorids.— -Bichloride of tin absorbs the 
vapour of anhydrous sulphuric acid in large quantity, and without evolu- 
tion of sulphurous acid, and when perfectly saturated with it, solidifies in 
a transparent and colourless mass. It dissolves dearly in a small quantity 
of water, with milky turbidity in a larger quantity. 

On distilling this mass, a colourless syrup (a) passes over and hardens 
into a transparent, colourless, brittle mass; a white mealy sublimate h col- 
lects in the neck of the retort; and an unfused mass (c) remains in the retort. 

a. The brittle mass forms with water a very turbid solution containing 
stannic oxide, hydrochloric acid, and sulphuric acid, with separation of 
white fiakes mixed with heavy oily drops; these dissolve but slowly 
in water, as sulphate of terchloride-of-sulphur; the flakes which remain 
behind dissolve readily in hydrochloric, sulphuric, or nitric acid. 

a s 6(SnC]s,BaO>) + 5(Sa*,5SOS). 

Or : H. Rose* 

6SaCP 778-8 »m 27*43 12Sn 7080 .... 24-93 .... 2507 

6SnO> 4500 .... 1585 30S 4800 .... 1690 .... 17*40 

5SCl» 611-0 .... 21-51 27a 9558 .... 3366 .... 3396 

25SO» 1000-0 .... 35-21 870 6960 .... 24-51 .... 

2839-8 .... 100-00 28398 .... 100-00 

Sometimes the compound contains less ^SnCP, SnO*), and in that case 
it dissolves in water with little or no turbidity. 

6. The mealy sublimate contains less quintosulphate of chloride-of- 
sulphur than a, and therefore forms no oil-drops or only a few, when put 
into water. 

<;. The residue in the retort, after being sufficiently heated, con- 
tains nothing but stannic oxide with sulphuric acid. The large quantity 
of stannic oxide arises from the simultaneous formation of terchlori<le 
of sulphur from the sulphur of the sulphuric acid. (H. Rose, Pogg. 
44, 320.) 

IT M. loDOCHLOBiDB OP TiN. — SnCl, SnI.— When a concentrated 
solution of stannous chloride is boiled with iodine, a deposit of stannous 
iodide is formed, and the liquid, after filtration and cooling, yields straw- 
yellow, silky crystals of the iodochloride. — These crystals are decom- 
posed by contact with water; they are not volatile. They contain 12-63 
per cent, of chlorine, 45*86 iodine, and 42*16 tin. (Henry, Fhil. Trans. 
1845; 363.) IT 



92 TIN. 



Tin and Fluorine. 

Htdrated Pbotofluoride of Tin, or Hydrofluate of Stannous 
Oxide. — Aqueous hydrofluoric acid, even when warmed, has no sensible 
action upon tin. The solution of stannous oxide in aqueous hydrofluoric 
acid, when evaporated out of contact of air, yields small, white, reiy 
brilliant crystals, which have a yery sour taste, and are easily soluble 
in water. (Gay-Lussao & Th^nard.) — Opaque prisms which taste first 
Bweet and then bitter; and when exposed to the air, are readily converted 
by oxidation into SnF', SnO^ (Berzelius, Fogg, 1, 84.) According to 
Unverdorben [N, Tr, 1, 36), hydrofluate of ammonia gives, with hydro- 
chlorate of stannous oxide, a precipitate consisting of glimmering, metal- 
shining laminsB^ soluble in dilute potash. 

B. Aqueous Bifluoride of Tin, or Hydrofluate of Stannic 
Oxide. — Aqueous hydrofluoric acid forms with stannic oxide a solution, 
which, when evaporated, gives off hydrofluoric acid, and is converted into 
an insoluble (basic 1) salt. (Gay-Lussac & Thenard.) The solution when 
boiled coagulatee like white of egg. (Berselius.) 



Tin and Nitrogen. 

A. Nitrate of Stannous Oxide, or Stannous Nitrate. — 1. Very 
dilute nitric acid, at ordinary temperatures^ dissolves tin in the form of 
stannous oxide, the action being attended, not with evolution of nitrous 
gas, but with formation of ammonia. (Proust.) — 2. By dissolving hydrated 
stannous oxide in dilute nitric acid, a salt is obtained not mixed with 
nitrate of ammonia. (Berzelius.)— 8. By precipitating protochloride of 
tin with nitrate of lead, and filtering to separate the chloride of lead. 
The solution is less liable to change, if mixed with excess of nitrate of 
lead. (Fischer, Sckw, 56, 360.) — Yellow solution, which if left to itself for 
some time, deposits a small portion of stannous oxide (gelatinous hydrate 
of stannous oxide, according to Berzelius), but if heated with fresh nitric 
acid, deposits the whole of the tin in the form of stannic oxide [anomalous 
hydrate of that oxide]. (Proust.) 

B. Nitrate of Stannic Oxide, or Stannic Nitrate.— The ordinary 
hydrate of stannic oxide dissolves abundantly in nitric acid, and neutra- 
lizes it completely. The solution has a bitter taste. If the acid used is 
rather strong, a portion of the salt separates from it in silky crystals. — 
At 50^ it deposits nearly all the oxide in the hydrated state, in gelatinous 
lumps, which dry up to a transparent and colourless mass; the oxide thus 
obtained behaves like ordinary hydrate of stannic oxide, excepting that 
it will not again dissolve freely m nitric acid, unless it be previously- 
treated with ammonia. If the solution contains nitrate of ammonia, it 
does not decompose at ordinary temperatures; if it does not contain that 
substance, and especially if it be much diluted, it deposits stannic oxide, 
which, however, disappears again on the addition of nitrate of ammonia. 
(Berzelius.) 

The anomalous hydrate of stannic oxide is completely insoluble 
in nitric acid, even if previously digested in ammonia. (Berzelius.) 



AMMONIO-BICHLOHIDE OF TIN. 63 

C. Nitric Oxide with Stannic Chloride.— Crystalline; easy to 
distil; decomposible by water. (Kuhlmann,) 

Hydrated stannous oxide is nearly insoluble in aqaeons ammonia, 
(Berzelios^ Pogg. 28, 444.)— In a large quantity of carbonate of ammonia, 
it dissolves almost completely. (Wittstem, RepeH. 63, 334.) 

D. Stannatb op Ammonia. — 1. The ordinary Hydrate of stannic acid 
dissolves in aqueous ammonia. The saturated solution evaporated over 
oil of vitriol in a receiver containing air leaves a yellowish jelly, contain- 
ing NH*0,2SnO', together with water. (Moberg.)— 2. Aqueous stannate 
of potash precipitates stannate of ammonia from a solution of sal- 
ammoniac. The gelatinous precipitate dissolves in pure water, but is 
reprecipitated by ammonia. The aqueous solution, when spontaneously 
evaporated, becomes viscid, but does not lose its transparency. (Berzelius.) 
-—The anomalous hydrate of stannic oxide does not dissolve in ammonia. 

E. Sulphosta^ate op Ammonium. — By dissolving hydrated stannic 
oxide in aqueous bihydrosulphate of ammonia. — No stannate of ammonia 
is thereby produced. (Berzelius.) 

F. Ammonio-protiodide op Tin. — 100 parts of stannous iodide 
absorb 20*9 parts of ammonia, evolving heat, and forming a white 
compound. (Rammelsberg, Pogg, 48, 169.) 

Rammelsberg. 

2NH» 34 .... 15-52 1729 

SnI 185 .... 84-48 82*71 



2NH»,SnI 219 .... 100-00 100-00 

G. Iodostannitb op Ammonium. — By precipitating tolerably concen- 
trated hydrochlorate of stannous oxide with hydriodate of ammonia.—- 
Greenish-yellow needles, decomposed by water, with separation of red 
iodide of tin. (P. Boullay.) 

Dried* Boullaj. 

NH«,HI 144 .... 28-01 29-02 

28al 370 .... 71-99 7 098 

NHn,2SnI 514 .... 100-00 ZZ 100-00 

H. Ammonio-protoohloridb op Tin.— -2 At. protochloride of tin 
absorb, when heated, 1 At. ammoniacal gas. (Persoz.) 

I. Ammonio-bichloride of Tin.— The fuming spirit of Libavius 
absorbs ammoniacal gas at ordinary temperatures, causing evolution of 
heat. (H. Davy.)— The solid mass, as it forms, must be assiduously 
pulverized, and again exposed to the ammoniacal gas, if we would 
ensure its complete saturation. (H. Rose.) The white mass may be 
sublimed without decomposition (even in hydrogen gas : H. Hose), and 
when heated in the air, evaporates in white pungent fumes. (H. 
Davy.) When dissolved in water it reddens litmus strongly. ^Grou- 
velle.) After sublimation, it is crystalline and has a somewhat yellowish 
white tint. When heated with sodium, it emits a brilliant violet light, 
and is resolved into granules of tin, chloride of sodium, and ammoniacal 
gas. It dissolves completely in cold water (Grouvelle, H. Rose), 
only that which has not been sublimed forming a turbid solution. 
The solution, if evaporated in vacuo over oil of vitriol, leaves the undo- 



94 TIM. 

composed compound in the form of a mass of crysiaLs^ wUcli gnblime 
without decomposition. Bat if the cold solution (which gives no tur- 
bidity with ammonia) be heated, or left to itself for a few days, it deposits 
a jelly. Sulphuric acid likewise gives a gelatinous precipitate, soluble ia 
a larger quantity of water. The same dbaracter is exhibited by aqueous 
bichloride of tin, to which a small quantity of ammonia has been added. 
The compound is not altered by phosphuretted hydrogen gas in the cold ; 
when heated, it gives off ammonia and turns red on the surface, probably 
from formation of a small quantity of chlorostannate of phosphurett^ 
tydrogou. (H. Rose, Fogg. 24, 163.) 

H. Rom. Panos. Grouvelle. 



9ubUmed» not iubUmed, 

KH' 170 .... 11-58 .... 10-92 .... 13-27 .... 20'46 .^ 20-94 

SnCP 129-8 .... 88-42 .... 8908 .... 8673 .... 79-55 .... 7906 

NH>,SnCP 146-8 .... 100-00 ,... lOO'OO .... 100*00 .... lOO'OO .... 10000 

The unsnblimed compound yields a laiger quantity of ammonia^ 
because free ammonia adheres to it. (H. Rose.) According to Grouvelle 
and Persoz {Ann. Chim, Fkys, 44, 322), the compound =2NH',SnCl», 

K. CHLOROSTANmTE OF Ammonihu. — This is the residue obtained 
when tin-filings are heated with sal-ammoniac, ammonia and hydrogen 
gas being evolved; at a higher temperature it sublimes. (Proust, JV'. GehL 
1, 249; Borzelius.) Regular octohedrons, which are permanent in the 
air, and redden litmus; their solution in water becomes turbid on boiling. 

(Apjohn.) 

Apjohn. 

NHKl 53-4 .... 34-06 84-1 

SnCl.... 94-4 .... 60-20 60-3 

HO 9-0 .... 5-74 5-6 

NH<Cl,SnCl + Aq 156*8 Z lOO'OO ZZ 100-0 

IT Poggiale {Compt rend. 20, 1180)) has formed a compound con- 
taining 2NHH71, SnCl+dAq; it crystallises in needles grouped in tufts, 
permanent in the air and decomposed by water, IT 

L. Chlorostakvatb of Ammoxiitm. — Pink SaU.-^l . Precipitated in 
the form of a white powder, on mixing concentrated solutions of bichloride 
of tin and sal-ammoniac. When a dilute mixture of the two solutions 
is slowly evaporated, the compound is deposited in small regular octo- 
hedrons and cnbo-octohedrons. (Bolley, Ann. Pharm. 39, 100.) It may 
also be obtained by mixing a solution of 40 parts of tin in aqua-regia 
with 35 parts of sal-ammoniac at 100°, evaporating to dryness, dissolving 
the perfectly dried residue, which amounts to 120 parts, in water, and 
leaving the solution to crystallize. (Wittstein, JRepert. 64, 7.) — 2. Sub- 
limes m transparent octohedrons during the preparation of mosaic gold 
with tin, sal-ammoniac, and sulphur, and may be purified by solution, 
filtration, and crystallization. (Gm.) The crystals decrepitate when 
heated, then evolve bichloride of tin, and afterwards sublime in white 
laminae. (Wittstein.) Dissolves in 3 parts of water at 14-5°. The con- 
centrated solution does not decompose on boiling; the dilute solution, 
when boiled, deposits the whole of the stannic oxide in white flakes. 
(BoUey.) 



STAKNATS OF FOTASH« 95 



NH* 


.... 18'0 


.... 


«70 & tt»< 

19-33 
70-85 


Bolky. 


CI 

SnCP 


35-4 
.... 129-8 


19-2 
70-9 


NH^CLSnCP 


.... 183-2 




10000 


1000 



M. Hydrochloratb and Stannite op Ammonia. — By suyersatn- 
rating aqueous protochloride of tin with ammonia till the precipitated 
stannous oxide is redissolved^ and evaporating the solution in vacuo^ this 
compound is obtained in crystals. (Berzelius.) 

N. NrniATB of Stannic Oxide and Ammonia.— -Nitrate of ammonia 
increases the solubility of stannic oxide in nitric acid; hence it is easier 
to dissolve tin without precipitation in nitric acid containing nitrate 
of ammonia. (Yid. NUrate of Stannic Oonide, p. 92; also Ann. Chim. 
42, 218.) 

Tin and Potasbiitm. 



A. Alloy of Tin and PoTAseiUM.— a. Seven volumes of tin-filings 
unite with 2 volumes of potassium, with faint incandescence, and form an 
alloy, which is somewhat less white than tin, brittle, of fine-grained 
fracture, and easily fusible. Oxidizes quickly in the air, effervesces with 
water, and still more with aqueous acids.— ^. With a larger quantity of 
potassium an alloy is obtained, which often, especially during pulveriza- 
tion, takes fire in the air. (Gay-Lussac & Th^nard.) — c. When granulated 
tin is ignited with cream of tartar, or 100 parts of stannic oxide with 
60 parts of tartar carbonized by roasting, and 8 parts of lamp-black 
(with 16 lamp-black a pyrophorus is formed), the tin takes up a small 
quantity of potassium, so that when thrown into water, it slowly evolves 
hydrogen gas. (Serullns, Ann. Chim, Fhft. 21, 200,) 

B« Stannitb of Potash.— Hydiated stannous oxide dissolves readily 
in caustic potash. The solution is resolved, especially when heated, into 
crystallized tin and stannate of potash* (Proust.) Zinc separates the tin 
from it in soft laminsa. (KlaprotL) When solution of potash is com- 
pletely saturated with nydrate of stannous oxide, and th^i left to 
evaporate in vacuo, the potash, at a certain decree of concentration, 
withdraws the water from the hydrated oxide^ which thereapou becomes 
insoluble and falls to the bottom. (Fremy.) 



G. Stannatb of Potash.— <x. Ordinatryj-^a. if<ma8tannaie.''-~l. By 
fusing stannic oxide or either of its hydrates with hydrate or carbonate 
of potash. If the fusion with carbonate of potash he interrupted before 
the carbonic acid is completely expelled, the same effect is produced as 
with titanic acid and carbonate of potash. (III. 484; H. Rose.) The 
fused mass generally contains an excess of potash. — 2. By diceolving 
stannic oxide, or the ordinary or anomalous hydrate in hot, strong potash* 
ley. The solution saturated with hydrated stannic oxide and then 
evaporated in vacuo over oil of vitriol to a considerable degree of con- 
centration, yields colourless, shining, oblique rhombic prisms, whose very 
acute lateral edges are often truncated; they have a caustic alkaline 
taste, do not deliquesce in the air, but absorb carbonic acid from it. 
Easily soluble in water whether hot or cold. (Moberg, Ben. Jahre^>er, 
22, 142; Ber. fiber d. Yenamml. d. Ifat^rf. in Frag. 1837.) The 



&d 



TIN. 



crystals tarn red wben heated, but do not melt. (Proust.) Lead immersed 
in the aqueous solution precipitates the whole of the tin. (Fischer, Fogg. 
9, 263.) Copper in contact with tin is quickly tinned by the solution. 
(Bottger, Ann. Fharm. 39, 171.) Alcohol added to the solution preci- 
pitates the salt /9. — IT Ordinary stannate of potash does not lose its 
solubility in water by ignition; acids added to the solution of the ignited 
salt, throw down stannic acid, perfectly soluble in nitric acid. (Fremy.) IT 

Anhydrout. Crystallized. Moberg. 

KO 47-2 .... 38-62 KO 472 .... 31-64 31-88 

SnO» 75-0 .... 61-38 SnO» .... 750 .... 5027 49-00 

3HO .... 270 .... 1809 1806 

KO,SnO« 122-2 .... 100-00 +3Aq. 149-2 .... lOO'OO 98*94 

p. Acid Scdt. — 1. By precipitating the aqueous solution of a with 
alcohol. — 2, When stannic salt is precipitated by carbonate of potash, 
hydrated stannic oxide containing potash is precipitated; and this, after 
the saline solution has been remoyed by decantation, dissolves in pure 
water, forming a milky liquid, which gives a precipitate with carbonate 
of potash. (Berzelius.) 

5. Anomalous, — Fremy's Meicutannate of Fotash, — When the ano- 
malous hydrate of stannic oxide is boiled with a yery dilute solution of 
potash, a solution is formed, containing 16 parts of stannic oxide to 
1 part of potash. The liquid, which appears bluish-white and opalescent 
by reflected, and deep yellow by transmitted light, becomes gelatinous on 
evaporation, and afterwards dries up to a deep yellow substance, which 
re-dissolves when treated with water. This substance is resolved by 
ignition into insoluble stannic oxide and a compound of potash with a 
small quantity of stannic oxide, which may be extracted by water. 
(Berzelius.) The anomalous hydrate dissolves imperfectly in aqueoua 
potash, and, when the solution is left to itself for some time, partly 
separates out again. It does not dissolve in aqueous carbonate of potash. 

iH. Rose, Anal. Ohem.) T Fremy prepares metastaxinate of 'potash by 
issolving metastannio acid (p. 73) in dilute potash-ley and adding solid 
caustic potash, whereupon the compound separates in the form of a white 
granular precipitate. This precipitate, when dried upon a porous porce- 
lain] plate, becomes resinous and translucent; it dissolves completely in 
water, forming an alkaline liquid which cannot be made to crystallize 
by evaporation, but on the addition of an acid, yields a precipitate of 
metastannic acid insoluble in nitric acid. Metastannate of potajdb, when 
heated with excess of caustic potash or left in contact with it for several 
da3r8, is converted into stannate of potash. By ignition it is dehydrated 
and decomposed. From the ignited salt, water extracts potash and only 
a small quantity of metastannic acid; 100 parts of the salt, after 
ignition and treatment with water, yield 79 parts of metastannic acid. 
Fremy assigns to this salt the formula K0,Sn<^0^H4H0. {N. Ann. CMm, 
Fhyz. 23, 393.) IT 

D. SuLPHosTANNATB OP PoTAssiUM.— KS,SnS*.— By dissolving anhy- 
drous or hydrated bisulphide of tin in hydrosulphate of potash. If the 
bihydrosulphate be used, the second atom of hydrosulphuric acid is given 
off with effervescence; if the sulphide of tin is anhydrous, a boiling 
heat is required to insure saturation. Caustic potash with bisulphide .of 
tin yields the same solution, likewise, however, containing stannate of 
potash. 



CHLOROSTANNATE^ OP POTASSIUM, 



97 



3Sii6S + 3KO » 2(KS,SnS?) + KO,Sn02. 

Pale yellow liquid. When digested with excess of hydrated bisulphide 
of tin, it converts the latter into sesquisulphide^ tin being deposited and 
sulphur dissolved, and a solution of polysulphide of potassium formed. 
Acids added to the solution of sulphostannate of potassium evolve hydro- 
sulphuric acid and precipitate bisulphide of tin: 

KS, SnS2 + HO + SO» = KO, S0» + SnS« + HS. 

For every 2*12 parts of bisulphide of tin (in the anhydrous state) which 
hydrochloric acid throws down from the liquid, there are formed 1 '63 
parts of chloride of potassium. Alcohol added to the yellow solution 
throws down a more concentrated solution of the same compound, in the 
form of a light yellow thickish liquid. (Berzelius.) 

E. loDosTANNiiB OF PoTASSiUM. — Concentrated solutions of proto- 
chloride of tin and iodide of potassium solidify when mixed, in conse- 
quence of the formation of yellowish silky needles; the same may be 
obtained, but in a finer state of crystallization, from a solution in hot 
alcohol. When chlorine gas is passed over the anhydrous salt, the tin 
burns with emission of light and forms bichloride of tin, leaving a 
residue of chloride of potassium. A small quantity of water withdraws 
iodide of potassium from the salt; the remaining iodide dissolves on the 
addition of more water. The compound dissolves in hot alcohol, leaving 
but a small quantity of iodide of tin behind, and the solution yields 
ciystals on cooling. (P. Boullay.) 



K 39-2 

2Sn 1180 

31 378-0 





Or: 




Boullay 


7-33 


Kl 


165-2 .... 30-87 ... 


33-76 


2205 


2SnI .... 


3700 .... 6913 ... 


66-24 


70-62 









KI,2SnI 535-2 



100-00 



535-2 



10000 100-00 



P. Chlorostai«nitb op Potassium. — 2KCl,SnCl+3HO. Needles. 
(Poggiale.) 

6. Ohlorostannate of Potassium. — By evaporating aqueous bichlo- 
ride of tin with chloride of potassium. «facquelain {Ann. Chim. Fhys, 
66, 130) dissolves equal numbers of atoms of chloride of potassium and 
bichloride of tin in water. Wittstein {Repert, 64, 7) adds 5 parts of 
chloride of potassium to a solution of 4 parts of tin in aqua-regia, or fuses 
1 At. anomalous hydrate of stannic oxide in a silver crucible with 1 At. 
hydrate of potash, and dissolves in hydrochloric acid. BoUey {Ann. 
Fharm. 39, 100) mixes dilute hydrochlorate of stannic oxide with excess 
of chloride of potassium. — Regular octohedrons (BoUey, Wittstein); 
rhombohedrons (Jacquelain). The crystals, which are permanent in the 
air, decrepitate when heated, give off bichloride of tin, and leave chloride 
of potassium mixed with a small quantity of stannic oxide (BoUey), or 
chloride (Wittstein). 

Jacquelain. Or : BoUey. 

... 1918 .... 19-42 KCl... 74-6 .... 36-5 .... 36*3 

... 28-86 .... 28-67 SnCl» 129-8 .... 635 .... 63-7 
..: 51-96 .... 51-85 



K. 39-2 

Sn 590 

3C1 106-2 



KCl,SnCP 204-4 



100-00 



99-94 



204-4 



100-0 



100-0 



TOL. V. 



H 



j-'j 



98 TIN. 

H. Htdroghloratb and Stanniteof Potash.— ^The liquid obtained 
by sapersaturating bydrochlorate of stannous ozido witb potasb till tbe 
precipitate is re-dissolved, yields crystals wben evaporated in racuo. 
(Berzelius.) 

Tin and Sodium. 

A. Alloy op Tin and Sodium. — Pour volumes of tin-filing unite 
with 1 volume of sodium at the melting point of tin — the combination 
being attended with evolution of light and heat — ^and form a white, 
very brittle, fine-grained alloy, which oxidizes in the air, and efiervesces 
with water and with aqueous acids. (Gay-Lussac & Thenard^ The alloy 
may likewise be formed by igniting tin with charred soap. (SeruUus.) 

B. Stannite of Soda. — Hydrated stannous oxide dissolves in aqueous 
solution of soda. 

C. St ANN ATE OP Soda. — a. Ordinary. — Solution of soda saturated 
with ordinary hydrate of stannic oxide yields — ^thouirh not without difli- 
culty — six-sided tabular crystals, which are lighter than the potash-salt 
and soluble in water. (Moberg.) 

Anhydroui. CryitaUixid. Moberjf. 

NaO 31-2 NaO 31-2 .... 2342 .... 235 

SiiO» 75-0 SnO» 75*0 .... 66-31 .... 56-0 

3HO 270 .... 20-27 .... 20-2 

NaO,SnO> 106-2 +3Aq 133-2 .... 100-00 .... 99*7 

If bydrochlorate of stannous oxide be precipitated at a temperature 
above 40"^ with excess of carbonate of soda, the filtrate, on cooling, 
deposits a compound, which effervesces with acids after being washed, 
and is therefore probably a carbonate of stannous oxide and soda. (Ley- 
kauf, J. pr, Ohem. 21, 817.) — IT. h, Metattannate, — Obtained by the 
action of concentrated soda-ley on metastannic acid. The salt is very 
difficultlv soluble in water, white, granular, and crystalline. It is resolved 
at 60° (or at a boiling heat, if in solution) into metastannic acid and 
soda. Its composition appears to be : NaO,Sn*0**' -f 4Aq. (Fremy.) f. 

D. SuLPHosTANNATE OF SoDiUM.-^imilar to the potassium-corn* 
pound. (Berzelius.) 

E. loDOSTANNiTB OF SoDiuM. — ^When a solution of iodide of sodium 
in concentrated bydrochlorate of stannous oxide is left to stand for some 
hours, it first deposits iodide of tin, and then pale yellow crystals of the 
iodostannite, decomposible by water. (P. Boullay.) 

F. Chlorostannate of Sodium.— By evaporating a mixture of 
bichloride of tin and common salt. According to Wittstein, 1 part of 
common salt with 1 part of tin dissolved in aqua-regia; or 1 At. anomalous 
hydrate of stannic oxide fused with 1 At. hydrate of soda, and dissolved 
in hydrochloric acid. Anhydrous, deliquescent cubes, which, when ignited, 
leave common salt with a small quantity of chloride of tin. (Wittstein.) 
Rhombic laminsB, which are permanent in cold air, effloresce in warm air, 
give off 12 or 13 per cent, of water at 100, and the chloride of tin at 



TIN AND . STRONTIUM. 99 

a red he^t. (BoUey.) It remains to be determined by analysis, whether 
the salts obtained by Wittstein and by BoUey differ in anything besides 
their quantity of water. Lewy has formed a compound containinfir 
NaCl,SnCP+5 Aq. ±-6 

G. Hydrochlorate and Stannite op Soda. — Analogous to the 
potash-compound. Delicate needles. (Berzelius.) 

. Tin and Barium. 

By heating tin to whiteness with baryta, strontia or lime, and charcoal, Gay- 
Lusaac and Th^nard did not succeed in forming alloys of tm with the metals of these 
alkalis. 

A. Stannate of Baryta. — Precipitated on mixing baryta-water or 
a barytar-salt with aqueous stannate of potash. The precipitate produced 
by baryta-water contains 209 (1 At.) baryta to 791 (4 At.) stannic acid. 
(Berzelius.) Moberg, by precipitating chloride of barium with stannate 
of potash, obtained a heavy white powder=BaO,SnO'+e Aq. 

B. SuLPHosTANNATE OF Bariuh. — Sulphostannato of potassium 
forms with baryta-salts, a light yellow precipitate soluble in water. 
(Berzelius.) 

C. loDOSTANNiTE OF Barium. — By dissolving stannous iodide in 
aqueous iodide of barium. Very soluble salt. (P. BouUay.) 

IT. D. Chlorostannitb op Barium.— BaCl,SnCl+ 4 Aq. Prepared 
*^y Poggiale. 

E. Chlorostannate op BARiuM.~BaCl,SnCP+5 Aq. Prepared by 
Lewy, IT. 

P. Hydrochloratb and Stannitb of BARYTA.—Analogous to the 
potash-H^ompound^ 

Tin and Strontium. 

^ A. Stannate of Strontia.— By precipitating stannate of potash 
with strontia-water or a strontia-salt. 

B. SuLPHosTANNATB OP Strontium.— As With barium. 

C. Iodostannitb of Strontium.— As with barium. 

IT. D. Chlorostannitb of Strontium. —SrCl,SnCl+ 4 Aq.—Pre* 
pared by Poggiale. 

E. Chlorostannatb of Strontium.-— SrCl,SnCP + 5 Aq.— Prepared 
by Lewy. T 

P- Hydrochi,orate and Stannitb of StttOi^TiA.— Analogous to the 
potash-compound. Delicate needles. (Berzelius.) 

b2 



IdO TIN. 



Tin and Calcium. 

A. Stannate op Lime. — Slowly precipitated when a lime-salt is 
mixed with stannate of potash. Contains CaO,SnO' + 4 Aq. (Moberg.) 

B. SuLPHOSTANNATB OF Calcium. — Analogous to the barinm 
compound. 

Tm AND MAaNESIUM. 

A. Stannate op Magnesia. — Stannate of potash precipitates from 
magnesia-salts a magma, which stops up the filter and cannot be washed. 
(Moberg.) 

IT. B. Chlorost ANNATE OP MAGNESIUM. — MgCl,SnCl' -f- 5 Aq. Pre- 
pared by Lewy. IT. 

C. Htdrochlorate and Stannite OF Magnesia. — Similar to the 
potash-salt. Deliquescent. 



Tin and Silicium. 

A. SiLiciDE OP Tin. — Tin fuses with silicium before the blowpipe, 
forming a ductile alloy, which, when dissolved in acids, leaves a snudl 
quantity of silica. (Berzelius, Pogg. 1, 220.^ 

Quadrosiiicate of soda precipitates bichloride of tin, but not the pro- 
tochloride. (Walcker.) 

B. SiLioo-PLUORiDB OF TiN. — Long prisms, very easily soluble in 
water. On evaporating the solution in the air, the stannous oxide is 
converted into stannic oxide, and is precipitated in combination with 
silica. (Berzelius.) According to Berzelius {Pogg, I, 200), this salt con- 
tains protofluoride of tin ; according to Berzelius*s Lehrhuch (4, 532), on 
the contrary (writing the formula in accordance with the numbers 
adopted in this ffand^ook), it is SnF',SiF'. 



Tin AND Tungsten. 

A. Tungstate op Stannous Oxide, or Stannous Tungstate. — 
Monotungstate of potash added to hydrochlorate of stannous oxide throws 
down a yellow powder, which gives off water and turns brown when 
heated, and bakes together at a red heat. Hydrochloric acid extracts 
from the powder the stannous oxide, which then converts the separated 
tungstic acid into blue oxide. The salt dissolves in oxalic acid and in 
potash, slowly in boiling phosphoric acid, and not at all in water. (Anthon, 
J, pr, Chem. 9, 341 .) 

ignited. Anthon. Unignited. Anthon. 

SnO 67 .... 35-83 .... 35*9 SnO .... 67 .... 27-8 .... 23 

W0» 120 .... 6417 .... 64-1 W0».... 120 .... 498 .... 60 

6H0... 64 .... 22-4 .... 22 

SnO,WO» .... 187 .... 10000 .... 1000 +6Aq. 241 .... 1000 .... 100 



• 



• 



«.«••'• 1 i 



STANNATE OF CHROMIC-OXIDE, )01 

B. Stannous SuLPHOTUKQ6TATE.*—SiiS,WS'.-*Volmnin6as browi^ 
flakes. (Berzelins.) 

C. Stannic SuLPHOTUNOSTATE.^SDS^WS^ — Greyish-yellow flakes. 
(Berzelins.) 

Tin and Molybdenum. 

A. MoLYBDATB OF Stannic Oxide, or Stannic Molybdatb. — Grey 
powder^ insoluble in water, but soluble in dilute hydrochloric acid with a 
bine, in concentrated hydrochloric acid with a green, and in aqueous 
potash with a brown colour; not altered by nitric acid. (Berzelins.) The 
blue precipitate, obtained by mixing an alkaline molybdate with stannous 
hydrochlorate, or by placing tin in contact with molybdic acid, water, 
and a yery small quantity of hydrochloric acid — Richter's Blue Carmine^ 
which was regarded by Buchob as a molybdanite of stannic oxide — is, 
according to Berzelius, nothing more than a mixture of stannic molybdate 
and blue oxide of molybdenum. 

B. Stannous SuLPHOMOLYBDATE."^Formed by precipitating a stan* 
nous salt. Black precipitate. 

C. Stannic Sulphomolybdatb.— By precipitating a stannic salt. 
The translucent brown precipitate becomes orownish-grey on drying. 

D. Stannous Pbrsulphomolybdate. — Hydrochlorate of stannous 
oxide is completely precipitated by an aqueous solution of the potassium- 
salt. The diark brown precipitate, when immersed in the liquid and 
exposed to the air, is conyerted into £, and dissolyes gradually, forming 
a red solution. 

E. Stannic Pbrsulphomolybdate.— Red precipitate, slightly soluble 
in water, in which it forms a red solution; hence, wneu it is precipitated, 
a portion remains dissolyed. (Berzelius, Pogg. 7, 287.) 

Alkaline VanadiattB give no precipitates with tiU'Salts. The yellow mixtore of 
Tanadiate of ammonia with hydrodilonte of ttannons oxide loses its oolonr after a while; 
the mixture of ▼anadiate of ammonia with hydrochlorate of stannic oxide remains 
yellow. (Bersdiiis.) "^ 

Tin and Chromium. 

A. StawRoU of Chromic Oxide 9 — a. By heating chromate of stan- 
nic oxide to bright redness, a dark yiolet mass is obtained, which 
communicates to glazings a yariety of tints, from rose-red to violet. 
(Leykanf, J. pr, Uhem, 19, 127.) — 6. Hyperacid SaU, — Mineral lac, 
Lacque mhiirale* 50 parts of stannic oxide yery strongly ignited with 
1 part of chromic oxide, yield a mass consisting of fine crystals and 
vitreous globules, of beautiful and very durable colour. — c. Hyperetcid 
Salt containing Stannate of Lime. — Fink-colour, — 100 parts of stannic 
oxide are strongly ignited for some bours with 34 parts of chalk and 
from 1 to 1^ pt. chromic oxide, or 3 to 4 chromate of potash (perhaps 
also with the addition of 1 part silica and 1 part alumina). The dingy- 
red mass is washed with water containing hydrochloric acid, and thereby 
acquires a beautiful rose-red colour. It is soluble in rather strong hydro- 



102 TIN.. 

^lorM acid, whioh is not ihe case with mineral lao; it is naed to pro- 
duce a red colour on Fayence, (Malaguti, Ann. Chim, Pky9. 61, 433.)-— 
d. Hydrated i — Monochroraate of potash added to hydrochlorate of stan- 
nous oxide throws down a green mixture of chromic oxide and stannic 
oxide. (Grouvelle.) 

B. Chrohate of Stannous Ozidb.— When hydrochlorate of stan- 
nous oxide is added to chromate of potash, the latter being in excess and 
the liquid, agitated, chromate of stannous oxide is precipitated in yellow, 
curdy flocks. (Berzelius.) On the contrary, when dilute chromate of 
potash is added by small portions at a time, and with constant agitation, 
to hydrochlorate of stannous oxide, a greenish-white precipitate is pro- 
duced, probably consisting of stannate of chromic oxide. If the tin^^ 
solution contains free acid, the whole remains dissolred, forming a green 
solution. 

C. Chbomatb ot Stannic Oxide. — Bi-hydrochlorate of stannic oxide, 
not containing any further excess of acid, forms a yellow precipitate 
with chromate of potash. The liquid above the precipitate acquires an 
(mfcnge-yellow colour, in oonsequenoe of the liberation of chromic acid. 
'—The precipitate, after drying, is brownish-yellow and translucent,, 
and is conyerted by ignition into violet-coloured stannate of chromic 
oxide. 

Tin and Manganese. 

Stannatb of Manoanous Oxidb.--— White powder, which gradually 
becomes dark brown by exposure to the air. (Berielitts.) According tq 
Uoberg, it acquires a yellow colour. 

Perman^nate of potash gives no precipitate with hydrochlorate of 
stannic oxide. (Fromherz.) 

Tin and Arsenic. 

A. Arsenide of Tin. — 1. When pulverized arsenic is stirred about 
in melted tin, combination takes place, attended with evolution of light 
and heat. (Gehlen, A. Vogel.) — 2. By heating tin with arsenious acid. 
(Gehlen.) — White, sonorous, and brittle, if the tin be not in too great 
excess; of laminar texture, and less fusible than tin.< — Gives off its 
arsenic when fused in an open vessel. With hydrochloric acid it evolves 
arseniuretted hydrogen gas. — ^When it is dissolved in hydrochloric acid, 
there remains a black compound of tin with excess of arsenic, which 
t(ives off its arsenic when ignited, and then dissolves again in acids. An 
alloy containing excess of arsenic is not attacked by hydrochloric acid. 
(Soubeiran.) 

B. Arsenite of Stannic Oaide or ArtenicUe of Stannoiu Oxide ?-^ 
1. Arsenic acid with acetate of stannous oxide, or arseniate of potash with 
hydrochlorate of stannous oxide, forms a white precipitate, insoluble in 
water. — 2. Tin dissolves in aqueous arsenic acid — arseniuretted hydrogen 
<being evolved — and forms a gelatinous mass. (Scheele.) 

0. Stannous Sulpharsenite. ^ By precipitating hydrochlorate of 
stannous oxide with a saturated solution of orpiment in faydrosulphate of 



ANTIMONIATB OF STANNIC OXIDB. 105 

soda. The dark brovn precipitate does not fuse when heated, l^ut gives 
off part of its orpiment, and leaves a grey, metallic, porous mass, 

D. Stannic Sulpharsbnitb. — The yellow, gummy precipitate ob- 
tained with hydroohlorate of stannic oxide, becomes orange-yellow on 
drying, yields a powder of a fine yellow colour, and behaves like C 
when heated. (Berzelins, Fogg, 7, 1 47.) 

E. Stannoits Sulpharseniate. — Both the bibasic and the terbasic 
snlpharsenite of sodium give dark chestnut-brown precipitates with 
hydrochlorate of stannous oxide. 

F. Stannic Sulpharseniate. — Both the bibasic and terbasic sodium- 
salts form, with hydrochlorate of stannic oxide, pale yellow, gummy pre- 
cipitates, which stop up the filter, and become orange-yellow on drying. 
(Berzelins, Pogg, 7, 28.) 

G. Bichloride of tin combines with terchlorlde of arsenic, the com- 
bination being attended with evolution of heat. (J. Davy.) 



Tin and Antimont. 

A. Antimonide op Tin. — Formed by fusing the two metals toj^ether 
—in which case the combination takes place without evolution of light 
and heat — or by fusing sulphide of antimony with excess of tin. 

a. 12 pts. tin to 1 antimony. The alloy called Pewter, used for 
making vessels to hold liquids. 

6. 10 pts. tin to 1 antimony. Perfectly ductile. (Chaudet.) 

c. 7 pts. tin to ] antimony. Produces a fine tone. (Kastner, Kcutn, 
Arch. 19, 324.) 

d. 8 pts. tin to ] antimony. Less ductile than tin; sp. gr. 7*059. 
(Chaudet.) 

e. 1'5 pts. tin to 1 antimony. Brittle, less laminar than a^timony« 
(Gehlen.) 

/. 1 pt. tin to 1 antimony. Extremely brittle; easily pulverised; sp. 
gr. 6*803. (Chaudet.) 

The ductile alloys are rendered brittle by the addition of a small 
quantity of lead. If the quantity of tin be not less than 9 times as 
great as that of the antimony, boiling hydrochloric acid extracts the 
whole of it (with evolution of antimoniuretted hydrogen 1), and leaves the 
antimony in the form of a black powder. (Chaudet, Ann. Chim. Phyi. S, 
376; also-y. Tr. 2, 1, 167.) 

B. Antimoniate op Stannic Oxide.— When hydrochloric acid in 
which antimonic acid and stannic oxide are dissolved together, is diluted 
with water, the two metallic acids are precipitated in combination, and 
the liquid loses nearly all the metal that it contained. (Thenard.) — If 
tin on the one hand, and antimony on the other, be heated with excess 
of nitric acid, till red fumes are no longer given off, and the two liquids 
be then mixed, the two white powders therein contained are converted 
into a yellow powder, with fresh evolution of nitrous vapours, — because 
the antimoniate of antimonio oxide fnitrate of antimonic oxide] formed 
from the antimony, becomes oxidizea and converted into antimonio acid. 



104 TIN, 

which then unites with the stannous oxide [stannic oxide]. (Lerol, 
iT. Ann. Chim. Phy%. 1, 504; also «/. pr. Ckem. 24^ 253.) 

C. Stannous Sulphantimoniate. — Schlippe's salt gives a dark 
brown precipitate with hydrochlorate of stannic oxide. (BAmmelsberg.) 

Tin and Tellurium. 

A. Tellubide of Tin. — Tellurium fuses with tin. 

B. Stannous Sulphotellurite. — The brown precipitate turns black 
on drying, and, when heated in a retort, gives off sulphur, and is con- 
verted into a grey mass having the metallic lustre. 

C. Stannic Sulphotellurite. — The precipitate is dark brown. 
(Berzelius.) 

Tin and Bismuth. 

A. Alloys op Tin and Bismuth. — An alloy of 177 parts (3 At.) 
of tin and 213 parts (1 At.) of bismuth, when cooled from a state of 
fusion, exhibits but one solidifying point — inasmuch as it first cools 
regularly down to 143°, and then remains at that temperature for a con- 
siderable time, till the latent heat set free in the solidification of the 
alloy, has had time to escape. But all other alloys of these metals like- 
wise exhibit a higher solidifying point (which may be distinguished as 
the FoinX of Separation), inasmuch as the excess of the one or the other 
metal [or rather — since the point is variable — ^another definite alloy con- 
taining an excess of one of the two metals] solidifies first, and afterwards, 
at 143^, the hitherto fluid alloy containing Sn^Bi. The higher solidify- 
ing point, or point of separation, is 190° for Sn^Bi, 160" for Sn^Bi, 150^ 
for Sn*Bi, 170° for Su*Bi^ and 190° for SnBi. (Rudberg, Pogg. 18, 240.) 

a. 40 parts tin to 1 bismuth; perfectly ductile; the addition of 1 part 
of lead diminishes its extensibility. 

b. 25 parts of tin to 1 bismuth. Slightly ductile. (Chaudet.) 

c. 8 parts tin to 1 bismuth. Fuses at 199°. (Lewis.) 

d. 3 parts tin to 1 bismuth. Pulverizable; of dull grey fracture, and 
specific gravity 7*776. Gives up all its tin with a small quantity of 
bismuth to heated hydrochloric acid. (Chaudet.) 

e. 2 parts tin to 1 bismuth. Fuses at 166**. (Lewis.) 

/. 236 parts (4 At.) tin to 213 parts (1 At.) bismuth. Sp. gr. 8*085. 
(Regnault.) 

g, 1 part tin to 1 bismuth. Perfectly brittle; pulverizable; of fine- 
grained fracture; sp. gr. 8*345. (Chaudet.) Fuses at 138^. (Lewis.) 
Expands strongly in solidifying. (Marx.) With hydrochloric acid it 
behaves like c£. (Chaudet, .inn. Chim. F/iys, 5, 142; also iT. Tr, 2, 2, 349.) 

k. 177 pts. (3 At.) tin to 213 pts. (1 At.) bismuth. Fuses between 
131° and 137°. (Dobereiner, Kastn. Arch. 3, 90.) 

i. 118 pts. (2 At.) tin to 213 pts. (1 At.) bismuth. Sp.gr. 8*759. 
(Regnault.) 

B. Allot op Antimony, Bismuth, and Tin. — ^236 parts (4 At.) 
tin to 213 pts. (1 At.) bismuth, and 129 pts (1 At.) antimony. Sp. gr. 
7-883 at 20**. (Regnault, ilnn. Chim. Fhys. 76, 136.) 



LEAD. 105 



Tin and Zinc. 

A. Allots of Tin and Zinc. — These two metals fuse together with 
ease; the alloy is harder than either tin or zinc^ and less extensible than 
tin. Sn*Zn has but one solidifying point, viz., at 204°. (Compare the 
obseryations made with reference to nismvih and Tin.) The other alloys 
exhibit in addition a higher solidifying pointy which varies according to 
the nature of the alloy. (Rudberg.) 





Sn^Zn Sn^Zn Sq^Zq Sn^Zn Sn^Zn SnZn 


Variable point .... 


210** .... .... 230** .... 250° .... 280*' .... 320** 


Fixed point 


204° .... 204'* .... 204° .... 204** .... 204° .... 204° 



B. St ANN ATE OF ZiNC-oxiDE. — Stannate of potasl^ yields ,with zinc* 
salts^ a white precipitate composed of ZnO^SnO' + 2 A<]. (Moberg.) 

Other Compounds of Tin. 

With Lead, Iron, Cobalt, Nickel, Copper, Mercury, Silver, Gold, 
Platinum, Pallskdium, and Iridium. As tin makes these metals brittle, it 
was called by the alchemists, Diabolm MetaUorum. 



Chapter XXXI. 



LEAD. 



Bucholz. Lead-oxide and its salts. A, GehL 5, 253. 

Thomson. Oxides of lead. A, Gehl, 4, 92. 

Berzelius. Gilb, 166 and 186; 46, 131. Further: Schw. 7, 71. 

Winkelblech. O^des of lead. Ann. Pkarm. 21, 21 ; also J, pr, Chem* 

10, 227. 
Bromeis. On the salts produced by the action of lead on the nitrate of 

lead-oxide. Ann. Pharm. 72, 38. 



Synonymes : — Blei, Fhmh, Plumbum, Satumus. 

History. — Known from the earliest times. 

Sources, — In the metallic state? — as red lead; as peroxide; as car- 
bonate, phosphate, sulphate, selenite, tung^tate, molybdate, ranadiate, 
chromate, and arseniate of lead-oxide; as aluminate of lead-oxide; as 
chloride of lead, sometimes united with oxide or carbonate; as selenide of 
lead; as sulphide of lead, either alone or associated with other metals, as 



IQfi XBAD. 

in Feaiher-ore, Zinkenite, Boulangerite^ Pla^oniie, Jamesonite, Oeocronite, 
Needle-ore, Kobellite, Boumonite, and Antimonial Copper-glance; as 
telluride of lead, sometimes associated with other metals, as in Foliated 
Tellurium and White Tellurium. Traces of lead have been found in sea- 
water (y. Ann. Ckim, Phy$, 28, 129); in coal (Ohem. Soc, Qu. J, 2, 1); 
and in the blood of animals {Jakresber. L. ds K, /., 874). 

Preparation an ike large scale. — 1. Native carbonate of lead, or arti- 
ficially prepared lead-oxide, e. g. litharge, ia fused in a smelting or a 
reverberatory furnace, in contact with charcoal, and often with the 
addition of lime. — 2. Galena is freed from part of its sulphur by 
roasting, either in heaps, or on hearths, or in calciniog furnaces, and the 
roasted ore, consistiug of lead, lead-oxide, sulphate of lead-oxide, and 
nndecomposed sulphide of lead, is fused in contact with charcoal, and 
'generally with addition of lime, in a smelting or a reverberatory furnace 
— ^whereby metallic lead and slags are produced, and mixed with 
them, a quantity of nndecomposed galena (leadstofie), which is again 
roasted and fused. Or the unroasted galena is smelted in a furnace with 
iron, iron-cinder, or an ore of iron, whereby metallic lead, slags, and 
jplumbiferous sulphide of iron are obtained; the latter is roasted and 
fused a second time. 

The lead thus obtained from the ore^ called Fig-lead (Werkbki), 
frequently contains gold and silver, to separate which it is oxidized on 
cupels, on which the gold and silver are left. The lead oxide thus 
obtained, called Litharge (Bleigldtte), is reduced as in (1) — the process is 
caUed the Reining of Litharge {das GldUe-Frischen) — and yields Refi^ned 
Lead. 

PurificcUion."--!, Nitrate of lead-oxide purified by repeated crystal- 
lization is ignited in an earthen crucible to expel the nitric acid, and the 
resulting oxide reduced by charcoal. — 2. Oxalate of lead-oxide ignited 
alone in a covered crucible yields lead free from charcoal. (Winkelblech.) 
3. Solution of sugar-of-lead is precipitated by sulphuric acid (in which 
process the acetic acid may likewise be obtained from it), and the sulphate 
of lead-oxide, after thorough washing, is strongly ignited in a covered 
crucible with 2 At. charcoal (Berthier); 152 parts of lead-sulphate 
intimately mixed with 12 parts of charcoal powder. The same result 
may likewise be obtained by igniting at a lower temperature 8 parts of 
lead-sulphate with 4 parts of potash and 1 part of charcoal,-— or, according 
to A. Werner (J. pr. Ohem. 13, 191), 16 parts of lead-sulphate with 9 
parts of Chili-saltpetre, 4 of resin, and 4 of charcoal powder, till the 
mass, after deflagration, yields no more bubbles. 

Properties. — Crystallizes in regular octohedrons. Mongez obtained 
lead, by slow cooling, in four- sided pyramids; Braunsdorf (J. pr. Chem. 
1, 120) obtained well-defined octohedrons; and Mai'x (Schw. 57, 193), by 
allowing a considerable quantity of melted lead to cool till half of it 
solidified, then making a hole in the crust and pouring out the still fluid 
portion, obtained it in fern -like forms similar to those in which sal- 
ammoniac crystallizes. Specific gravity 11-3305 (Kupfi'er); 11*352 
(Brisson, Herepath); 11 358 (Morveau); 11*3888 (according to Karsten, 
when purified by method 1); 11*445, when in the utmost attainable state 
of purity (Berzelius). According to Morveau, the denbity of lead is 
rather diminished than increased by hammering, in consequence of the 
formation of cracks; if, however, the metal is prevented from expanding 



SUfiOJUDI OF JJUlD. 107 

on oitbitt fflde, its density increajses from 11 '358 to 11*388. Lead is soft, 
Fery tough, and makes a mark on paper; it may easily be out with a 
imife or rolled into plates, but not drawn into thin wires. By repeated 
fusion in an open vessel, it is rendered harder and more bHttle, because 
it becomes mixed with oxide. (Cariolis, Ann. Ckim, Fhys, 44, 103.) It 
has a bluish-grey colour and strong lustre. Fuses at 262'' (Biot), at 282'' 
(Newton), at 812^ (Morveau), at 322° (Dalton, Crichton), at 325° 
(Rudberg), at 334° (Kupffer). Begins to volatilize at a very strong red 
heat, and boils a,t a white heat. 

Atomic weight of Lead, 103-56. (Berzelius, Pogg, 19, 300,) 

Compounds of Lead, 

Lead and Oxygen. 
A. Suboxide of Lead? Pb*6. 

Remains when oxalate of lead-oxide is cautiously heated in a retort 
from which the air is excluded. (Dnlong. S<Jiw, 17, 229; Boussingault^ 
Ann. Chim, Pkys, 79, 108; also J. pr. Chem. 2, 162; Pelouze, Ann, 
Chim. Fhys. 79, 108; also J. pr. Chem. 25, 486.) The retort must 
be heated in the oil-bath to a temperature not exceeding 300°, the heat 
being continued as lone as any gas is given off: the gas thus evolved is a 
mixture of 1 vol. caroonic oxide with 3 vol. carbonic acid, excepting 
towards the end of the operation, when, if the heat be somewhat increased 
in order to finish the decomposition, the gas evolved becomes somewhat 
richer in carbonic acid. (Pelouze.) The whole is suffered to cool before 
the suboxide is removed. It forms a black powder, sometimes dull, 
sometimes having a velvety lustre. (Pelouze.) It contains no metallio 
lead, for mercury extracts nothing from it, either dry or under water. 
(Boussingault, Pelouze.) Neither does it contain any yellow oxide of 
lead; for the aqueous solution of common sngar-of-lead does not extract 
^uy lead-oxide from it on boiling. (Pelouzei^ But the suboxide, when 
heated to doll redness, out of contact of air, is resolved into a greenish- 
yellow mixture of lead and the yellow oxide. (Boussingault, relouse.) 
After this treatment^ mercury extracts lead from the substance, and a 
boiling solution of sugar-of-lead or acetic acid leaves the lead in the form 
of a net- work, which, when pressed together between the fingers, forms a 
dense mass having the metallic lustre. (Pelouze.) When heated in the air 
it takes fire and bums with a glimmenng light, producing 103*6 parts of 
yellow oxide, according to Boussingault; and from 103*6 to 103*7 
according to Pelouze. Dilute sulphuric, nitric, hydrochloric, or acetic 
acid, resolves the suboxide into yellow oxide which combines with the 
acid, and very finely divided metallic lead. (Boussingault, Pelouze.) The 
same effect is produced by a solution of mononitrate of lead-oxide; a hot 
solution, on the contrary, takes up the whole of the suboxide and forms 
basic nitrate of lead-oxide. (Pelouze.) The suboxide, when moistened 
with water, rapidly absorbs oxygen from the air, and is converted into 
the white hydrated oxide, the action being attended with rise of tempe- 
rature. (Boussingault, Pelouze.) A mixture of finely divided lead and 
litharge does not yield the same result. (Pelouze.) Winkelblech, by 
heating oxalate of lead-oxide, obtained a greyish-black powder which 
contained at most 1 per cent, of oxygen, and from which mercury dis- 
solved lead; it was therefore a mixture of lead with a small quantity of 



108 LEAD. 

ibe yellow oxide. This anomalous result is attributed by Pelouxe to the 
too great beat wbicb Winkelblecb applied to tbe oxalate. Tbe grej film 
wbicb forms on tbe surface of lead heated to a temperature short of the 
melting point) is likewise regarded by Berzelius as a suboxide* 

Calculation, according to Bonisingtiilt and Pelonie* 

2Pb 208 96-29 

Q 8 371 



Fb'O ^16 100-00 



B. Lead-Oxibe. PbO. 

Protoxide of Lead, YeUaw Oxide of Lead, Massicot, Oxide Plombiqae, 
Bleioxyd. 

Formation. 1 . Lead heated in the air till it volatilizes bums with a 
white ligbt^ and is converted into this oxide: Flowers of Lead, Bleiblumen, 
Flores Plumbi. — Lead reduced in thin metallic laminse by the action of 
hydrogen gas at a gentle heat on finely crystalline lead -oxide, remains 
unaltered in the air at ordinary temperatures, but takes fire when heated, 
and bums with a feeble glow till it is converted into the protoxide. 
(Winkelblecb.) — Lead, when heated in the air, becomes covered with a 
CTey film, and, if the surface be continually renewed, is wholly converted 
into Lead-ash (Bleiasche), a yellowish-grey, pulveralent mixture of 
metallic lead and yellow oxide, which, if heated in the air for a longer 
time, is whoUy converted into the latter. — 2. In dry air at ordinary 
temperatures lead retains its lustre; in damp air, it becomes dull, assum- 
ing first a yellowish-brown, then a blue, and lastly a grey tint. (Bonsdorff, 
Po^g, 41, 305.) Under water in an open vessel, lead is converted into 
the hydrated oxide which partly dissolves in the water, and by absorbing 
carbonic acid from the air, is transformed into the hydrated carbonate. 
Cuttings of lead placed in a closed vessel with water and air freed from 
carbonic acid, and left at rest, form white flakes of hydrated lead-oxide, 
and the water becomes saturated with that oxide. If the vessel be shaken 
for half an hour, no hydrate is formed, but the lead-cuttings become 
covered with suboxide, and in that case, aerated water exerts no further 
action upon them, even if carbonic acid be likewise present. (Bonsdorff.) 
When lead in contact with water is exposed to the open air, white clouds 
of hydrated oxide consisting of soft silky scales are soon formed. (Wetzlar, 
JSckw. 54, 324.) Platinum wire wound round the lead-plate accelerates 
the oxidation. (Fischer, Kastn, Arch, \7, 382.) These white scales con- 
sist of hydrated carbonate of lead-oxide; if the access of air is but partial, 
and consequently the process goes on slowly, the compound is obtained 
in silky laminas. The finest crystals are obtained by cutting some bright 
places on a piece of lead tamished by exposure to the air, and then 
immersing it in water; a silky vegetation then forms on the bright parts 
of the lead, and on removing this formation, the surface is found to be 
marked with crystalline devices (moir6). Bonsdorf. — In water containing 
a trace of sulphate of potash, nitre, or common salt, lead merely becomes 
marked with a few isolated spots ; and if the water contains a larger 
proportion of salt, only a slight tarnishing is produced. (Wetzlar.) In 
saline solutions, oxidation goes on more slowly than in pure water, and 
the resalting product is not a loose powder, but a salt of lead closely 



LEAD-OXIDE. 10* 

adhering to the surfSetce of the metal. (Fischer.) Nitrates prevent the 
white turhidity only when they are in large quantity ; of other salts, 
small quantities are sufficient : the purer, therefore, the water, the more 
does it become turbid by exposure to the air in contact with lead- 
cuttings. ^Bonsdorff.) — 3. Lead decomposes vapour of water at a white 
heat and is converted into the protoxide. (Regnault, Ann. Chim, Phys. 
62, 363.) It does not decompose water at a red heat (Bonsdorff); 
neither does it decompose water acidulated with sulphuric acid at a boil- 
ing heat; but with boiling hydrochloric acid it evolves hydrogen gas.— 
4. With nitric acid and heated oil of vitriol it yields a lead-salt. 

Preparation on the large scale, — 1. Massicot is obtained by heating 
lead to low redness on a flat hearth, and continually removing the film 
of oxide as it forms, till the lead-ash at first obtained is, for the most 
part, converted into the yellow oxide ; the latter is then freed from the 
still remaining metallic portions by grinding and levigation. — 2. Litharge 
is obtained in the oxidation of pig-Had containing gold and silver — the 
resulting lead-oxide, which is generally contaminated with silica, ferric 
oxide, cupric and cuprous oxide, autimonic oxide, and other oxides, is 
fused by the high temperature, and solidifies in a scaly, shining mass, 
sometimes of a yellowish tint (A rgj/ritis, Silher-glatu), sometimes rather 
inclining to red {Chrysitis, Ooldgldtte), The oxides of copper may bo 
completely removed by digesting the levigated litharge with aqueous 
solution of carbonate of ammonia. (Bischof, Sckw. 64, 65). — The auti- 
monic oxide is left behind on dissolving the litharge in boiling nitric 
acid, and may then be dissolved in hydrochloric acid. (Anthon, Repei't, 
58, 387.) — ^ The difiference between red and yellow litharge is attri- 
buted by Leblanc (iT. J, Pharm. 8th Sept., 1845) to a mere diversity of 
physical structure, not of chemical composition; for either modification 
may be obtained at pleasure by properly regulating the temperature and 
the rate of cooling; the red variety, which is specifically lighter than the 
yellow and more crystalline substance, is formed most abundantly when 
the cooling is slow. IT 

Preparation on the small scale. By gently igniting pure crystallized 
nitrate, or perfectly pure carbonate or oxalate of lead-oxide, in a vessel 
to which the air has access. 

Properties. Lead-oxide appears to be both dimorphous and amor- 
phous. It occurs in pale yellow rhombic octohedrons (or dodecahe- 
drons?) and cubes, and a red amorphous powder. — By the following pro- 
cesses, lead-oxide may be obtained in the crystalline state: 1. By slow 
cooliuff after fusion. Litharge when quickly cooled, solidifies in a mass of 
crystalline scales ; but the portion which remains on the muffle some- 
times crystallizes in yellow, translucent, six-sided tables (Marx); in 
rhombic octohedrons with a distinct plane of cleavage (Mitscherlich); in 
rhombic dodecahedrons, the angles of which are indefinite, in consequence 
of the curvature of the faces (Gaultier de Claubry & Beudant, Ann. 
Chim. Phys.). White lead fused by the blowpipe-flame on a copper plate 
or other non-reducing support, crystallizes in scales on cooling; but from 
the middle of it there generally shoots out a mass, half a line long, some- 
times in the form of a triangular pyramid, sometimes in that of a nearly 
perfect rhomboidal dodecahedron, of a hyacinth-red tint while hot, becom- 
ing snlphnr-yellow and translucent as it cools, and opaque and dull when 
perfectly cold. This alternate fusion and crystallization may be repeated 



1 10 LEAD. 

several times.^ — 2. By fosion with hydrate of potash. If 1 part of lead- 
oxide and from 4 to 6 of hydrate of potash be fused for a short time in 
a siirer crucible at an incipient red heat, and the mass after cooling 
exhausted with water, the lead-oxide remains in the form of cubes and 
square tables. (Becquerel, Ann. Ckim, Pkyn. 51, 105.)— 3. By treating 
lead-oxide with potash or soda-ley. From a solution of leaa-oxide in 
soda-ley, saturated while hot, placed in a stoppered bottle, and then left 
to itself all through the winter, the iead-oxide crystallizes in small, white, 
translucent rhombic dodecahedrons. (Houton-Labillardiere, J. Pharm. 3, 
335.) The crystals are rhombic octohedrons, having the same angles as 
those obtained by fusion. (Mitscherlich.) Strong boiling potash-ley satu- 
rated with lead-oxide, yields, on cooling, yellow scales similar to those of 
litharge; if the potash-solution is less fully saturated with lead-oxide, or 
if it has deposited the excess of that oxide in scales, no further deposition 
takes place till after perfect cooling, whereupon red scales are thrown 
down, perfectly soluble in acetic acid, and therefore free from minium; if 
these scales are heated, they turn yellow on cooling. Hence it appears 
that litharge may have a red colour without containing minium or red 
oxide of copper. (Mitscherlich, J, pr. Ghent. 19, 451.) — Boiling soda-ley 
of 40^ — 41 B, saturated with hydrate of lead-oxide, yields rose-red 
crystals of that oxide on cooling. These crystals yield an orange-yellow 
powder, similar to that of litharge. At about 400° they turn black, 
increase in bulk, decrepitate with loss of 0*1 per cent, of water — and 
when heated to low redness, assume a sulphur-yellow colour without 
changing their form. While still in the red state, they dissolve, though 
very sparingly, in nitric acid, either concentrated or dilute. (Calvert.) — 
if hydrated lead-oxide be boiled with a quantity of aqueous alkali not 
sufficient to dissolve it, the undissolved portion becomes converted into 
crystalliue anhydrous oxide; the resulting solution when evaporated, 
yields more crystals of the anhydrous oxide, distinguished from the for- 
mer portion by their easy solubility in alkalis even when dilute. (Fremy, 
N. J. Pharm. 3, 30.) — 4. By precipitating a lead-salt with excess of 
alkali. Solution of sugar-of-leiid mixed with excess of ammonia and 
exposed to the sun for a few days, yields olive-green, very hard crystals 
of anhydrous oxide. (Tiinnermann, Kastn. Arcli, 19, 339.) Behrens 
{N. J. Pharm. 4, 18) supersaturates the sugar-of-lead solution with a 
quantity of ammonia sufficient to re-dissolve the precipitate; filters to 
separate any carbonate of lead-oxide that may have been formed; puts 
the filtrate into a stoppered bottle; and exposes it to the rays of the sun. 
After a few hours, transparent crystals make their appearance, colourless 
at first, but afterwards becoming yellowish, and finally yellowish-grey. 
Their powder is white, but assumes a dark brown-red colour after lonff 
trituration. — 4 measures of sugar-of-lead solution saturated at 30% mixed 
with 100 measures of boiling water, and then with 45 measures of aqueous 
ammonia, deposit, in the course of half a minute, a large number of very 
delicate, yellowish- white, rhomboidal laminss, having a silvery lustre and 
united in tufts; these laminas must be separated by levigation from the 
crystalline granules of hydrated oxide which fall down at the same time, 
then washed with boiling water, and dried in vacuo. When ignited, 
they do not give oS any water — or only a trace of it, with decrepitation 
-^neither do they lose their transparency. They may be obtained with- 
out admixture of hydrate, by boiling 100 measures of a saturated solution 
of tris-acetate of lead-oxide with 50 measures of water, adding thereto a 
mixture of 50 measures of water at 80% and 8 measures of aqueous 



LEAD-OXIDE. Ill 

ammonia^ and heatinff ihe miztnre in the water-lath. In the course of a 
mlnate^ crystals of tne oxide separate^ free from hydrate, the formatioti 
of the latter being prevented by the high temperature. (Payen, Ann. 
Chim. Phy$, B6, 54; also J, pr, Chetn. 13, 485.) — By mixing at a boiling 
heat the solntions of 1 At sngar-of-lead and 1^ At. potash in a tenfold 
quantity of water, the oxide is obtained in delicate reddish-yellow 
tfptmglea having the metallic lustre. (Winkelblech.) If solution of sugar- 
o^-lead be dropt, with agitation, into strong lime-water heated to 88°, till 
crystalline scales make their appearance, and a small quantity more be 
then added, the scales increase rapidly in number aa the liquid cools : 
when dry, they are yellowish-white, with a silvery lustre, and like talc 
to the touch ; when ignited they turn red, without loss of weiffht^ but on 
cooling regain their original colour, shape, and lustre. (Brendecke, JRepert, 
55 f 318.)— 5. By placing lead in contact with air and water. On the 
bottom of a leaden vessel filled with water, there are first formed a num- 
ber of white flakes of hydrated dicarbonate of lead-oxide, then shining 
grey crystals of anhydrous oxide, partly in scales like mica, partly in 
rhombic dodecahedrons with cube-faces. When heated they become 
opaque and orange-coloured, but without losing weight or lustre. (Yorke^ 
PhU. Mag. J. 5, 82,) 

Lead-oxide is obtained in the amorphous state, by throwing the 
hydrated oxide into fused hydrate of soda and washing tne residue, when 
cold, with water. Red mass, of the colour of minium, and yielding a 
reddish-yellow powder; between 300° and 400^, it assumes a orown-red 
colour, which it retains after cooling; but if heated above 400°, it 
becomes sulphur-yellow on cooling. It is distinguished from the crystal- 
lixed red oxide by its very ready solubility in acids. (Calvert, Uompt. 
rend. 16, 361.) 

Lead-oxide, in its ordinary state, is either a lemon-yellow or a 
reddish-yellow powder. This may perhaps be regarded as the powder 
of the oxide in its yellow crystallized s1»te. It assumes a brown-red 
colour whenever it is heated. Specific gravity 9*2092 (Karsten); 9*277 
(Herapath); after fusion, 9*50 (Boullay). Lead-oxide fuses at a red 
heat, and on cooling, solidifies in a mass of crystalline scales; according 
to Marx, it expands in solidifying. It does not solidify to a glass on 
cooling, unless it contains silica. (Fuchs, Scfiw, 67,429.) A trace of silica 
added to fused oxide of lead, renders it vitreous. (Biewend, J, pr. Ckem. 
23, 250.) A similar effect is produced by fusion in an earthen crucible. 
The glass has a density of 8 '01 (Le Royer & Dumas); it is transparent 
and yellow, or if metallic lead [or the suboxide ?] be present, green. 
(Proust.) Lead-oxide volatilizes at a white heat, butless easily according 
to Fonmet (Ann. Chim. Phys. 55, 414), than metallic lead. According to 
Brendecke, lead-oxide turns reddened litmus blue. 

BertMer. DUbereioer. Yaaqadm. J. Da?y. 

Pb 104 .... 92-857 .... 93*3 .... 93-02 .... 93 .... 9285 

O 8 .... 7-143 .... 6-7 .... 6.98 .... 7 .... 7-15 

PbO 112 .... 100-000 .... 1000 .... 100-00 .... 100 .... 100*00 

Berzelins. Bacholz. Trommsdorff. Promt. Thomson. Richter. 

Pb 92-828 .... 92-59 .... 91-01 .... 91 .... 90-5 .... 88-5 

7-172 .... 7*41 .... 8-99 .... 9 .... 9-5 .... 11-5 



100000 .... 10000 .... 10000 .... 100 .... 1000 .... 1000 
(PbO » 1294-5 + 100 » 1394*5. Berzelias.) 



112 LEAD* 

Decompo»itiofi8. 1. Lead-oxide is reduced to the metallic slate by 
charcoal (very easily, and with intumescence on charcoal before the 
blowpipe), by carbonic oxide and by hydrogen at a low red heat. The 
crystalline oxide obtained by precipitating a hot sugar-of-lead solution 
with potash is reduced by carbonic oxide or liydrogen gas at a tempera- I 

ture not much aboye 100*^. (Winkelblech.) Hydrogen gas first produces ' 

the dark grey suboxide, afterwards, at a low red heat, metallic lead* 

iBerzelius.) The reduction of lead-oxide at a strong red heat in crucibles 
N. Gehl. 4, 98) is due to the action of carbonic oxide gas which pene- 
trates the crucibles. By potassium and sodium, at temperatures some- 
what below the melting points of these metals, lead-oxide is reduced, 
with yivid ignition, to the metallic state. By antimony, to the metallic 
state. By cyanide of potassium, to cyanate of potash and metallic lead 
(Liebig.) — 2. By heating with sulphur, lead-oxide is conyerted into 
sulphurous acid and a mixture of oxide and sulphide of lead. — 3. By 
chlorine- water, into peroxide and chloride of lead: 2PbO-|-Cl=PbO*-|- 
PbCl. Similarly by bromine. (Lowig.) — 4. Lead-oxide fused in excess 
with metallic sulphides, sometimes decomposes them with formation of a 
sulphate, as with barium; sometimes with eyolution of sulphurous acid, 
as in the case of the heayy metals. The metal of the metallic sulphide 
either unites directly with the lead, or it is conyerted into oxide, and 
fuses together with a portion of the lead-oxide, while pure lead separates 
out; with a smaller quantity of lead-oxide, sulphide of lead is produced 
as well as the metal, while part of the other metallic sulphide remains 
undecomposed, and fuses into a slag with the metallic oxide produced 
and the excess of lead-oxide. (Berthier.) — .1 pt. Svlphide of BaHum and 
2 to 4 pts. litharge yield without fusion a black slag, consisting of baryta 
and lead-oxide, which may be extracted by acetic acid, and likewise of 
sulphate of baryta, sulphide of lead, and metallic lead. With 30 pts. 
litharge, the sulphur is completely oxidized, and forms sulphate of 
baryta. — 1 pt. Sulphide of Manganese, with 4 pts. litharge, eyolyes 
without fusion a large quantity of sulphurous acid, and yields , a black 
slag, the lower part of which contains lead and sulphide of lead. With 
6 pts. litharge, the mass becomes soft and doughy, and a brown sla^ is 
formed, still containing a large quantity of sulphide of manganese, with 
separation of So parts of brittle lead. With 20 parts of litharge, the 
mixture fuses readily, and yields a hyacinth-red glass, together with 6 '2 
parts of ductile lead. With 30 parts of litharge, 6*6 parts of lead «aepa- 
rate out (consequently the sulphide of manganese is perfectly oxidized), 
and aboye it a brown-red glass. — Tersulphide of arsenic yields very 
fusible mixtures with litharge; but unless the quantity of litharge equals 
from 20 to 30 times that of the orpiment, only a part of the sulphur is 
volatilized in the form of sulphurous acid: 52 parts of orpiment and 279 
of litharge yield, without separation of lead, a black mass, having the 
metallic lustre and a granular fracture. With 558 pts. litharge, a similar 
slag is formed, and below it 40 parts of ductile lead free from arsenic. 
W^ith 1023 pts. litharge, the separated lead amounts to 300 parts, and 
the slag is dense, black, and shining. With 1302 pts. litharge, 360 pts. 
lead are obtained, together with a brown-black, translucent slag. With 
1673 pts. litharge; 450 pts. lead and a hyacinth-red glass. With I960 
pts. litharge: 470 pts. lead, and a pale hyacinth-red glass. But it is 
only when the quantity of lead-oxide amounts to 3120 parts, that the slag 
resembles litharge in appearance, and is perfectly free from sulphide of 
arsenic. — Tersulphide of Antimony has a strong tendency to fuse with 



LEAD-OXIDE. 113 

litharge, bat the sulphar is not completely oxidized anlesa the quantity 
of litharge is 25 times as great as that of the antimonious sulphide. 
1 part of antimonious sulphide and 3*8 pts. litharge yield 0*2 lead and 
a dense, black, very fluid slag. With 6 pts. litharge: — 0*9 pts. lead with 
the same slag. With 10 litharge: — 1*6 lead, with a slag which has pre- 
cisely the composition of lead-scum. With 140 litharge: — 5 lead and a 
hyacinth-red glass. With 250 litharge: — 5*7 lead and a mass resembling 
litharge. — 1 pt. Sulphide 0/ Bismuth, yields with 2*56 pts. litharge, an 
alloy of lead and bismnth, and a black crystalline-granular slag. With 
5'12 litharge:— -2*48 alloy and a dark-grey granular slag. With 10*24 
litharge: — 3*25 alloy, containing 24*5 per cent, of bismuth, and a greenish- 
yellow mass resembling litharge. — 1 pt. Sulphide of Zinc {Blende) with 
4*65 litharge, forms a doughy mass, and yields 2*4 parts 01 brittle lead 
(containing traces of zinc and sulphur) and a black, metal-shining slag 
containing sulphide of lead. With 6*07 litharge: — 2*96 brittle lead, and 
a very fluid, black, opaque slag. With 10 litharge: — 4*3 ductile lead 
and a dark-grey slag. With 25 litharge: — Q'5 pure lead and a yellow 
translncent glass. With this proportion of litharge, both the zinc and 
the sulphur are completely oxidated. — 1 pt. Stannic Sulphide and 5 pts. 
litharge, yield semi-dnctile metallic lumps, containing sulphide of lead, 
sulphide of tin, and metallic oxides. With 12 pts. litharge: — 3*6 lead and 
a hyacinth-red glass. With 20 litharge: — 5*4 lead and a similar glass. 
With 30.. 50 litharge: — 6 lead and a similar glass. (Berthier, Ann. Vhim, 
Phys. 39, 244.) 

Combinations, a. With Water. — ». Hydrate of Leadroxide, — Bright 
lead, exposed to the action of pure water and of air free from carbonic 
acid, forms white flakes of hydrate. rBonsdorfl*.)— 2« The hydrate may 
be prepared by dropping sugar-of-lead solution into excess of ammonia 
till the precipitate becomes permanent, then washing it and drying at a 
gentle heat. (Tiinnermann, Kastn, Arch, 19, 338.) Trisacetate of lead- 
oxide may also be used. The precipitate must be washed out of contact 
of air, and dried in yacuo at 15°. (Payen, Ann. Chim, Phys. 66, 49; also 
J", pr. Chem. 13, 484.) — 3. By mixing 4 measures of water saturated at 
30^ with sugar-of-lead, with 400 measures of boiling water, and then 
addinff 4 measures of aqueous ammonia. Together with the crystals of the 
anhydrous oxide (pp. 110, 111), there are likewise deposited denser crys- 
talline grains of the hydrate, which may be separated by levigation. 
(Payen.) To obtain larger crystals, 100 measures of water saturated 
at 2.5^ with trisacetate of lead-oxide, and diluted with 60 measures of 
water freed from air by boiling, are mixed with 4 measures of ammonia 
diluted with 60 measures of water also freed from air by boiling and 
then cooled, and the mixture kept for some time at a temperature 
of 30°. The crystallization begins in an hour, and is finished in 
24 hours. (Payen.) — ^5. By precipitating sugar-of-lead, or some other 
lead-salt, with potash or soda. (Mitscherlich.) Mulder {J. pr. Ohem. 
1 9, 79), after pouring off the liquid, boils the precipitate for some time 
with potash, and dries it at 100^. According to Winkelblecb, potash 
added to nitrate or acetate of lead-oxide, even when in excess and aided 
by heat, does not precipitate the hydrated oxide, but a basic salt. 

Hydrated lead-oxiae is a white powder. When examined by the 
microscope, it is seen to consist (I) of transparent and colourless four-sided 
prisms — or, if precipitated from the trisacetate— of little stars formed 
by the union of four octohedrons; (2) of short, four-sided prisms with 
four-sided summits; (3) of regular octohedrons. (Payen.) The hydrate 

TOL. V. I 



114 LEAD. 

tarns reddened litmns-paper blue. (Berzelins, ^ogg, 25, 396.) It retains 
its water and its colour at temperatures somewliat above 100^ (Mits- 
cherlich.) According to Tiinnermann, it acquires a brownish-yellow tint 
at a temperature below 100°. At 130° it begins to give off its water, 
and at 145° the whole of the water escapes, quite free from acetic acid, 
pure oxide being left behind. (Payen, J. pr. Chem. 17, 197.) It is 
dehydrated by boiling with strong potash-ley. (Bottger.) 

Tiinnermann. Mitscherlich. Payen. Mulder. 

(2) (5) (2-4) (5) 

3PbO 336 .... 97*39 .... 96*07 .... 96*5 .... 97*35 .... 9731 

HO 9 .... 2*61 .... 3-93 .... 3*5 .... 2*65 .... 2-69 

3PbO,HO .... 345 .... 10000 .... 10000 .... 1000 .... 100*00 .... 10000 

IF Schaffner (Ann, Fharm. 51, 175), by precipitating acetate of lead- 
oxide with potasn, obtained a hydrated oxide containing 96*40 lead-oxide 
and 3*60 water, corresponding to the formula, 2PbO-hHO. IT 

/3. Aqueous Solution of Lead-oxide.'-^l, Clean lead in contact with 
water and air free from carbonic acid, yields a solution of lead-oxide 
which turns reddened litmus blue, gives a faint red tint to turmeric, is 
turned brown by sulphuretted hydrogen, and gives white precipitates 
with sulphuric acid and with several salts. Water freed from air by 
boiling does not dissolve lead when kept in contact with it in a close 
vessel; water which has been agitated with air becomes charged with 
lead-oxide in the course of two hours, the quantity dissolved amounting 
to between tt^x^ and ttsito' ^^ ^^^^ slightly reddens turmeric, and turns 
reddened litmus blue; becomes turbid when shaken up in a half-filled 
bottle, or when boiled; yields lead at the negative and peroxide at the 
positive pole when acted upon by the electric current; gives a brownish- 
black precipitate with hydrosulphuric acid; becomes turbid immediately 
with carbonic acid (the turbidity, however, disappearing when the acid is 
in excess), or with sulphuric acid, or acid sulphate of potash or soda; more 
slowly with the neutral sulphates; becomes turbid when mixed with 
sulphate of lime or common salt, and slowly with nitre; forms with 
iodide of potassium a white cloud, which turns yellow on the addition of 
a small quantity of very dilute hydrochloric acid, together with a yellow 
precipitate; with chromate of potash, it forms a yellow precipitate on 
the addition of acetic acid. Spring-water of tolerable purity, two pounds 
of which contain only If grains of salts and no carbonic acid, likewise, 
when passed through a leaden tube 150 feet long, dissolves a quantity of 
lead sufficient to give a brown colour with hydrosulphuric acid. If a 
bright iron nail be driven through a leaden plate, and the whole immersed 
in water containing air, a white crystalline substance forms on the lead, 
and the water becomes charged with lead-oxide, while the nail does not rust 
at all in the immediate neighbourhood of the lead, and much less on the 
other parts of its surface than another nail immersed alone in the water. 
(Ph. Yorke, Phil Mag, J, 5, 82; abstr. Fogg. 33, 110.) Distilled water 
in contact with lead and with air free from carbonic acid, dissolves ^^^^^^ 
lead-oxide, acquires an alkaline reaction, and becomes turbid on exposure 
to the air, in consequence of the formation of hydrated dicarbonate of 
lead-oxide. (Bonsdorff, Fogg. 41, 306.) Wetzlar found that aerated 
water, after being placed in contact with lead, gave a very slight pre* 
oipitate'with hydrosulphuric acid, but no alkaline reaction. The presence 
of small quantities of carbonic acid, sulphuric acid^ or of various salts. 



LEAD-SALTS. 115 

prevents tbe solution of the lead-oxide, or greatly diminishes the quantity 
dissolved: this was first observed by Morveau. — 1 volume of water 
charged with ^ vol. carbonic acid gas dissolves a mere trace of lead-oxide 
in the form of carbonate, which may be detected by hydrosulphuric acid, 
and the lead remains quite bright; this water, after boiling, again exerts 
a solvent action if exposed to the air. Spring- water, 10 pounds of which 
contain 1*21 gr. chloride of sodium and chloride of calcium, together 
with 6'4 gr. carbonate of lime dissolved in excess of carbonic acid, pro- 
duces a slight deposit of brownish oxide on the surface of the lead, but 
does not dissolve any. (Yorke.) When lead is immersed in water con- 
taining sulphate of potash, common salt, or nitre, and exposed to the air, 
the water takes up a mere trace of lead-oxide, recognizable by hydrosul- 
phuric acid. (Wetzlar.) The greater the purity of spring-water, the 
greater is the quantity of lead which it dissolves, and the less fit are 
leaden pipes for conducting it. Leaden pipes should not be used for the 
purpose unless lead remains untarnished after 24 hours' immersion in the 
water; they are unfit for conducting water containing less than innnr ^^ 
its weight of salts. If the quantity of salts exceeds this limit, and the 
salts consist mainly of sulphates and carbonates, leaden pipes may be 
used; but if they consist chiefly of chlorides, even 1 part in 4000 is not 
sufficient to prevent the solution of the lead. (Christison, PkU, Mag. J, 
21, 158.)- — 2. Lead-oxide dissolves in water, forming the same solution. 
Scheele {Opusc, 2, 283), by placing litharge in water contained in closed 
vessels, and agitating occasionally for several days, obtained a solution 
which gave precipitates with carbonic and sulphuric acid. Lead-oxide 
obtained by igniting the nitrate, yields, when shaken up with water, a 
filtrate which has a faint, sweetish-bitter taste, turns reddened litmus 
blue, and is rendered turbid by carbonic acid, sulphuric acid, sulphates, 
common salt, and nitre; these re-agents, however, leave a portion of 
lead-oxide in solution, for the filtrate turns brown wben treated with 
hydrosulphuric acid. (Wetzlar, Schw, 54, 324.) 

The solubility of pure lead-oxide in water is denied by Tiinnermann 
(Kastn. Arch, 19, 338), Brendecke {Bepert. 53, 155, and 313), Siebold 
(lieperi. 53, 174), and Herberger {Repert, 55, 55). The discrepancy 
between the results obtained by these observers and those already given, 
appears to arise from their having generally left the water which they 
placed in contact with lead, its oxide, or its hydrated oxide, freely 
exposed to the air, and likewise to their having sometimes strained 
through double or quadruple filters exposed to the air all the time. Under 
these circumstances, the l^ui-oxide dissolved in the first instance, may have 
been precipitated by the carbonic acid in the air. 

b. With Acids, forming the Salts of Lead-oxide, or Lead salts. — 
Lead-oxide has a considerable affinity for acids. Lead-salts are colourless, 
unless they contain a coloured acid, and of great specific gravity. Those 
which are soluble in water have a sweet astringent taste and redden 
litmus. They sustain a red heat without alteration, unless the acid is 
very volatile or decomposible. When heated with carbonate of soda or 
charcoal before the blowpipe, they yield a button of lead. Their 
aqueous solution is precipitated in metallic dendrites, forming the Lead- 
tree, Arbor Saturni, by zinc, cadmium, and tin, and slowly by iron. The 
action of zinc and cadmium is immediate and complete. Zinc, however, 
does not precipitate lead from an alcoholic solution of sugar-of-lead. Tin 
ceases to act as soon as it becomes covered with lead; if the nitrate be 

i2 



116 LEAD. 

tlie salt used, stannic 6xide is afterw^ards precipitated togetlier with 
basic nitrate of lead-K>xide. Iron gives a precipitate with lead-acetate* 
(also with the trisacetate, Pajen, Ann, Chim. Phys. 54, 273), bat not till 
after some time, and on exposure to the air the lead is sometimes preci- 
pitated in large crystals; on nitrate of lead-oxide, iron acts only under 
the same circumstances as on stannous salts (p. 70). Manganese 
immersed in lead-acetate throws down a brown powder. (Fischer, Oilh. 
72, 289; Pogg. 9, 262; 10, 603.) The quantity of lead-oxide in the 
nitrate solution must be at least equal to -Yi-sm ^° order to give a • 
perceptible indication of reduction by zinc. (Harting.) Lead-acetate 
dissolved in 100... 500 parts of water, mixed with hydrochloric acid and 
kept from contact of air, is not precipitated by copper, which only 
contracts a few spots even at a boiling heat; but if the air has access to 
the solution, the lead is precipitated in the form of a black powder. 
(Reinsch, J, pr. Chem. 24, 248.) Phosphuretted • hydrogen gas slowly 
precipitates from lead-salts a brown phosphide of lead. (H. Rose.) 
Hydrosulphuric acid throws down black sulphide of lead, or if the lead- 
solution is very dilute, colours it brown. The limit of the brown colour- 
ing is attained, when 1 part of lead-nitrate is dissolved in 100,000 parts 
of water (Pfaff); when 1 part of lead (in the form of nitrate) is dissolved 
in 200,000 parts of water (Lassaigne); when 1 part of lead-oxide (in 
the form of nitrate) is dissolved in 350,000 parts of water. (Harting.) 
If the solution of the lead-salt contains free hydrochloric acid, the pre- 
cipitate is red or yellow, and a larger quantity of hydrochloric acid 
prevents it altogether. A solution of 1 part of lead-acetate in 200 parts 
of water mixed with 5 parts of hydrochloric acid of specific gravity 
1*16S, gives, with hydrosulphuric acid, a brown precipitate which soon 
turns black; with 10 parts of hydrochloric acid, an immediate red 
precipitate which soon turns brown and afterwards black; with 20 parts 
of hydrochloric acid, a carmine-red precipitate is gradually formed, which 
retains its colour and consists of sulphide and chloride of lead; and with 
30 to 50 parts of hydrochloric acid, a slight precipitate, but only after 
the addition of water. (Reinsch, Reperi, 5hy 183.) A solution of 1 part 
of lead-acetate in 112 parts of water, mixed with 14 parts of hydro- 
chloric acid, gives a yellow precipitate with hydrosulphuric acid. (Reinsch, 
Bepert. 56, 183.) Sulphuretted hydrogen water mixed with a large 
quantity of hydrochloric acid gives with lead-salts a red precipitate 
which soon turns black. (H. Rose.) Paper saturated with a lead-salt 
and then thoroughly dried, is not olackened by sulphuretted hydrogen 
gas. (Pamell, J, pr. Chem, 26, 190.) Aqueous alkaline hydrosulphates 
Hkewise throw down from lead-salts a black precipitate of lead-sulphide, 
insoluble in excess of the alkaline hydrosulphate. Sulphide of cadmium, 
and likewise the hydrated sulphides of manganese, iron, cobalt, and 
nickel, throw down sulphide of lead ft'om lead-salts. (Anthon.) — Hydriodic 
acid or iodide of potassium added to a solution of a lead-salt, not too 
dilute, throws down orange-yellow iodide of lead, soluble in a large 
excess of iodide of potassium. — Bromide of potassium gives a white 
precipitate with lead-salts. (Boland.) — Hydrochloric acid and its salts 
precipitate chloride of lead only from somewhat concentrated solutions; 
the precipitate is a white crystalline powder, soluble in a large quantity 
of water and also in potash. A solution containing 1 part of Tead-nitrate 
in 100 parts of water is the most dilute in which hydrochloric acid will 

* By the simple term had*aeetaU, ia to be understood the imk/to/ acetate, or common 
eugsLr-of*lead« 



LEAD-SALTS. 117 

produce a precipitate. ^Pfaff.)-^BroiDine colours lead-salta yellowish- 
brown, and, even when aaded in small quantity, throws down yellowish- 
brown peroxide of lead [with bromide?] on the application of heat. 
S Simon.) Chlorine- water added in lar^e quantities and heated, throws 
[own brown peroxide of lead; an aqueojos mixture of chlorine and 
bromine produces an immediate precipitate. (Simon.) Chloride of soda 
produces a reddish-yellow precipitate of sesquioxide of lead, which, when 
heated, is converted into the brown peroxide. (Winkelblech.) — Ammonia 
gives with lead-salts a white precipitate, which is either the hydrated 
oxide or a basic salt, and is insoluble in excess of ammonia. — Potash 
throws down white hydrate of lead- oxide, soluble in a large excess of 
potash, especially when heated. — Carbonate of ammonia, potash, or soda 
(the bicarbonates with efierrescence), throws down white carbonate of 
lead-oxide, insoluble in excess of the precipitant, but soluble in caustic 
potash. A solution of 1 part of lead ^in the form of nitrate) in 50,000 
parts of water is rendered slightly milky by carbonate of soda; with 
100,000 parts of water a slight opalescence is produced after five minutes, 
and with 200,000 parts of water, after ten minutes. (Lassaigne.) — Phos- 
phate of soda ^ives a white precipitate soluble in potash. — Sulphuric 
acid and its salts throw down white, finely pulverulent sulphate of lead- 
oxide. This precipitate is insoluble in cold dilute acids; it is distin- 
guished from sulphate of baryta by the blackening which hydrosulphate 
of ammonia produces in it. Lead-oxide is likewise completely precipi- 
tated by sulphuric acid from a dilute solution containing excess of hydro- 
chloric or nitric acid, provided the sulphuric acid is added in considerable 
ouantitr. (Wackenroder, Repert. 46, 225.) 1 part of lead-oxide (in the 
/orm of nitrate) dissolved in 20,000 parts of water is still plainly indi- 
cated by sulphuric acid added in excess (Pfaff, Halting, J, pr, Chem, 
22, 51); 1 part of lead (in the form of nitrate) dissolved in 25,000 parts 
of water gives an opalescence with sulphate. of soda after a quarter of an 
hour. (Lassaigne, •/. Chim. Med. 8, 581.)— Chroroate of potash gives 
with lead-salts a yellow precipitate of chromate of lead-oxide. This 
precipitate is insoluble in dilute nitric acid; it turns red when digested 
with ammonia; a basic lead-salt gives a yellowish-red precipitate. The 
limit of the reaction is attained with 1 part of lead-oxide in the form 
of nitrate, dissolved in 70,000 parts of water. (Harting.) — Arseniate of 
soda throws down white arseniate of lead-oxide.— Oxalic acid and alkaline 
oxalates give a white precipitate of oxalate of lead-oxide. The precipi- 
tation by alkaline oxalates takes place even in a solution diluted 100,000 
times. (Vhff.) Oxalic acid fives a precipitate, even in solutions con- 
taining excess of acid, provided they are dilute. (Wackenroder.) — Tinc- 
ture of galls forms a straw-yellow, and ferrocyanide of potassium a white 
precipitate. With 1 pt. in 8000. (Pfaff.) — Bromate and chlorate of 
potash, and likewise ferricyanide of potassium give no precipitate with 
lead-salts. — Those lead- salts which are insoluble in water dissolve, for the 
most part, in nitric acid. The carbonate, phosphate, and sulphate are 
likewise soluble in a cold dilute solution of sal-ammoniac (Brett.) 

e. With certain Salifiable Bases. The compounds prepared in the 
dry way have sometimes a vitreous appearance. From the aoueous 
solutions of the compounds of lead-oxide with the alkalis, zinc throws 
down the lead in the metallic state. These compounds may be called 
Flumhitea. 

d. With Chloride of Lead. 

e. With Resin* Starch, Onm, Sugar, and certain other non-acid 
organic eabstancee. 



118 LEAD. 



B. Red Oxidb op Lead. Pb»0*=2PbO,PbO». 

Bed Leady Minium, Blethyperoxydul, Deutoxyde de Plomh. — Forraa- 
tion. — 1. By keeping the protoxide at a dull red heat for a considerable 
time in the air. Red lead is likewise produced — ^after previous formation 
of hydrated and aqueous lead-oxide, and hydrated dicarbonate of lead- 
oxide— when lead-shavings are strewn upon water, the vessel being 
loosely covered and then set aside for some months; the formation takes 
place principally on those surfaces of the lead which are exposed to the 
air. In a similar manner, drawings made with lead turn red in the 
course of twenty years, (v. Bonsdorff.) 

Preparation on the large scale. — Finely pounded massicot (or litharge) 
is heated for 24 hours or more, either on the flat hearth of a reverberatory 
furnace, or in vessels lying horizontally and having wide mouths projecting 
from the side-openings of the furnace, the mass being frequently stirred 
and the heat not allowed to rise above dull redness. Litharge is too 
dense for the purpose and oxidizes but very imperfectly; massicot like- 
wise, even after eight firings, each continued for 24 hours, is far from 
being completely converted into red lead; the softer oxide obtained by 
heating white lead, oxidizes much more quickly and completely. Red 
lead prepared from massicot by one firing of 24 nours contains 8*26 p. c. 
oxygen, and when ignited yields 1*17 p. c. oxygen gas; it contains 50 
per cent, of real minium, and when treated with nitric acid yields 17-4 per 
cent, of brown peroxide of lead. After 2 firings, these quantities become 
respectively: 8-30; 1-22; 52-1 and 18-2;— after 3 firings: 8-43; 13*6; 
58-1 and 20'3;— after 4 firings: 8'56; 1-50; 64-1 and 22-4; — after 5 
firings: 8*61; 1-05; 66-2 and 23-];— and after 8 firings: 8*79; 175; 
74'8 and 26'0. On the other hand, minium prepared from white lead by 
3 firings contains 9*24 per cent, of oxygen, gives off 2*23 per cent, of 
oxygen gas, contains 95 '3 per cent, real minium, and when treated with 
nitric acid, yields 33 '2 per cent, peroxide of lead. If the minium thus 
prepared be moderately heated in a current of oxygen gas, it afterwards 
evolves 2*40 per cent, of oxygen on ignition. (Dumas, Ann, Chim, Fhys, 
49, 398.) 

To free commercial red lead from the yellow oxide mixed with it, 
Dumas digests it repeatedly with solution of lead-acetate; Berzelius and 
Dalton recommend treatment with cold, very dilute acetic acid; Phillips 
recommends 144 pts. at most, of strong acetic acid diluted with a large 
quantity of water to 100 of minium, inasmuch as if more acid be used, 
the brown peroxide is likewise formed. According to Dumas, however, 
peroxide of lead is always formed in the purification of minium, before 
the whole of the free protoxide is extracted, even when the dilutest 
acetic acid is employed. 

Commercial red lead likewise contains all the foreign metallic oxides 
— such as the oxides of copper, iron and silver — with which the maasicot 
or litharge used in preparing it is contaminated. — Red lead is likewise 
often adulterated with oxide of iron, red bole or brick-dust ; these sub- 
stances remain undissolved when the red lead is digested in warm dilute 
nitric acid to which a little sugar has been added; boiling hydrpchloric 
acid extracts sesquioxide of iron from the residue. When red lead thus 
adulterated is ignited, there remains a mixture of yellow lead-oxide and 
the red substances that have been added to it. 



RED OXIDB OF LEAD. 119 

On the small scale, red lead may be obtained by the following pro^ 
cesses. — 1. When 4 parts of lead-oxide prepared by igniting white lead 
are heated in a silver or platinum crucible with 1 part of chlorate of 
potash and 8 parts of nitre (the latter acting as a flux and thereby saving 
the chlorate), brown peroxide of lead is first obtained j but this, when 
further heated to dull redness, is converted, with intumescence and thick- 
ening of the mass, into red lead. As soon as the red lead begins to 
decompose at the edge of the crucible, the mass is suffered to cool, and 
the red lead well boiled with water containing potash. — 2. By boiling 
peroxide of lead with aqueous plumbate of potash, or 1 part of the per- 
oxide with 5 parts of lead-nitrate and a quantity of aqueous potash or 
soda sufficient to re-dissolve the hydrate of lead-oxide nrst precipitated, 
till a brown-red mixture of minium with a small quantity of the peroxide 
is produced, and digesting this mixture, after washing, with oxalic acid, 
which decomposes the peroxide without acting on the minium. [The 
product may contain oxalate.] The minium obtained by this process is 
rather dark-coloured, but it oecomes brighter when rubbed up with 
water J it haa the same composition as that which is obtained by th« 
ordinary method. (Level, Ann. Chim, Phy^, 75, 108; also, J, pr. (jhem^ 
22, 38.) 

Scarlet, crystalline-granular powder ; when heated, it first assumes a 
finer red colour, and then turns violet. Specific gravity 8*62 (Karsten), 
8-94 (Muschenbroek), 9*082 (Herapath). 

ThomsoD* BerzeUns. Bnmas. Vanqnelin, 

3Pb ^ 312 .... 90-7 .... 88 .... 90 .... 90-63 .... 91 

40 32 .... 9-3 .... 12 .... 10 .... 937 .... 9 

IVO*. 344 .... 1000 .... 100 .... 100 .... lOO'OO .... 100 

Or: Or: 

2PbO 224 .... 65-12 PbO 112 .... 32-56 

PbO» 120 .... 34-88 PbH)» 232 .... 6744 

2PbO,Pb03.... 344 Z, 10000 PbOjPb^O'.... 344 Z 10000 

Decompodtiom, I. By rather strong initios, it is resolved into 
yellow lead-oxide and (2*4 p. c: Dumas) of oxygen gas. — 2. By many 
oxiJizable bodies, at various temperatures, it is reduced to the yellow 
oxide. Aqueous sulphurous and hyponitric acid at ordinary tempera- 
tures, convert it respectively into sulphate and nitrate of lead-oxide; 
snlphurons acid acts very slowly in the cold, but rapidly on the application 
of heat. Protochloride of tin converts it, with a rise of temperature of 13% 
into chloride of lead and stannic oxide. (A. Vogel, Kastn. Arch,, 23, 84.) 
It is likewise reduced by boiling with a solution of sugar. — 3. With 
heated oil of vitriol, it yields sulphate of lead-oxide and oxygen gas. — 
4. With nitric acid, dilute sulphuric acid, and likewise by weaker acid?, 
such as acetic acid, it yields peroxide of lead and a salt of the protoxide. 
(Berzelius.) With a small quantity of strong acetic acid, red lead forms 
a white mass, which dissolves in a large quantity of the acid, forming a 
colourless liquid, from which peroxide of lead is gradually deposited. 
(Berzelius.) By treating common red lead with dilute nitric acid at ordinary 
temperatures, Longohamp {Ann, Chirn^ Fhys, 34, 105) obtained 16*66 
per cent, of peroxide, and at 80% 16*2 p. c; from minium crystallized 
in fine lamina, Hoiito&-Labillar<^^re, by treating it with nitric acid, 
i^btained 25 per cent.' of peroxide; Phimps {JPhiU. Mag. J. 3, 125) by 



120 LEAD. 

heating commercial minium with dilute nitric acid obtained 24*8 p. c 
and by boiling it with moderately strong acetic acid, 25 8 p. c. of per* 
oxide ; but minium preyiously purified by cold dilute acetic acid yielded 
with nitric acid, 34 per cent. (For Dumas' results, vid. p. 119.) By 
heating with nitric acid, a portion of the brown oxide is decomposed 
and partly dissolyed, forming a yiolet-coloured solution. (LevoL)-^ 

5. By a small quantity of hydrochloric acid, red lead is conrerted inta 
chloride of lead, peroxide of lead, and water : 

Fb»0< + 2HC1 = 2PbCl+PbO« + 2HO. 

By a larger quantity of hydrochloric acid, into chloride of lead, chlorine 
gas and water : 

IVO« + 4HC1 = 3PbCl + CI + 4H0. 

6. By chlorine- water, into chloride and peroxide of lead : 

Pb>0< + CI = PbCl + 2PbO». 

Similarly with bromine-water. (Lowig.) — Minium is not decomposed by 
mercurous nitrate or oxalic acid. (Levol.) 

C. Sesquioxide of Leadf Pb»0». 

Chloride of soda throws down from lead-salts, a reddish-yellow mixture 
of sesquioxide and chloride of lead, which, if warmed or left to stand for 
some time, turns brown from formation of peroxide. To obtain tbe 
sesquioxide free from chloride, nitrate of lead-oxide is supersaturated 
with potash in sufiicient quantity to re-dissolve the precipitate, and then 
treated with chloride of soda ; or the precipitate obtained by treating 
acetate of lead- oxide with a slight excess of potash is dissolved in caustic 
potash (after pouring off the liquid), and the clear solution mixed with 
chloride of soda. The yellow precipitate, when washed and dried, yields 
a soft, non-crystalline, reddish-yellow powder. This powder contains 
more or lets hygroscopic water closely united with it, and only to be got 
rid of by drying over vitriol with the aid of heat, whereupon it gradually 
escapes. At a red heat, the sesquioxide is resolved into 3*4685 per cent, 
of oxygen gas, and 96*5315 per cent of protoxide. By oxalic acid and 
by formic acid it is reduced to the state of protoxide, with evolution of 
heat. With nitric, sulphuric, hydrofluosilicic and acetic acids, generally 
without the application of heat, it is converted into peroxide and a salt of 
the protoxide. It dissolves in cold hydrochloric acid, forming a yellow 
liquid from which it is again precipitated by alkalis : the liquid, however, 
resolves itself in a few minutes into chloride of lead and free chlorine. 
(Winkelblech.) 

li^iikelblech. 

2Pb 208 .... 89'66 89-64 

30 24 .... 10-34 10-36 

Pb«0* 232 .... 10000 ZZ 10000 



D. Peboxidb of Lead. PbO\ 

Broum Oxide of Lead, Puce Lead, Bleihyperoxyd, Tritoxyde de Plomb. 
•^Discovered by Kurella and Scheele. — ^Found native in the form o£Meavy 



PEROXIDB OP LEAD* 121 

iead-are {Sehwerbleierz), — Formation and Preparation, 1. Solutions of 
lead-ealta deposit the peroxide in crystalline scales on the positive polar 
wire of the voltaic circuit (I. 463). The deposition of the peroxide takes 
place even in a solution containing only 1 part of lead in 12,000. 
(Fischer, Kcutn. Arch, 16, 219.^ — 2. By treating the yellow protoxide 
with chlorine-water ^Vauquelin) or hromine-water, or aqueous hypo- 
chlorous acid. — 3. Dilute suhacetate of lead-oxide mixed with aqueous 
hypochlorous acid deposits very finely divided peroxide of lead. (Pelouze.) 
•—4. By heating the aqueous solution of a lead-salt with chloride of soda. 
To a boiling solution of sugar-of-lead, chloride of soda is added as long as 
any precipitate is formed; the solution is then decanted, and the chloride 
of lead, which is precipitated at the same time, is extracted by boiling 
dilute nitric acid. The peroxide of lead thus obtained is somewhat 
lighter than that prepared by the ordinary method, but has the same 
composition, and contains no water. (Winkelblech.) — 5. By fusinff lead- 
oxide with chlorate of potash. (Qobel, Schtv. 67, 77; Liebig & Wfthler, 
Fogg. 24, 172.) The preparation is made by fusing in a silver or pla- 
tinnm crucible, 4 parts of lead-oxide (obtained by heating white lead) 
with 1 part of chlorate of potash and 8 of nitre, till the mass becomes 
uniformly black— an effect which generally takes places simultaneously 
with perfect fusion — the residue is then well washed with water, and 
treated with dilute nitric acid. Red lead substituted for the protoxide 
dues not yield any peroxide. (Level, Ann, Chim, Fhys. 75, 108.) — 
6. Litharge heated in a platinum crucible yields peroxide of lead and an 
alloy of lead and platinum. (Chevreul, Ann, Chim, Fhys, 80, 315; 
also GUb, 51, 115.) — 7. By treating red lead with chlorine-water. 
Chlorine gas is passed into water in which red lead is suspended — the liquid 
being frequently agitated — as long as any absorption takes place; and the 
resulting peroxide is continually washed with boiling water to free it 
from chloride. — 8. By treating red lead with nitric acid, which extracts 
the protoxide of lead. The red lead is first boiled for a sufficient time 
with excess of dilute nitric acid, and the resulting peroxide washed with 
water. — 9. By fusing red lead with hydrate of potash. (Becquerel, Ann. 
Chim, Fhy9, 51, 104.) The potash certainly extracts protoxide of lead. 
Berthollet {Stat, Chem. 2, 377) remarked that red lead evolves no oxygen 
when fused with hydrate of potash. 

The native peroxide occurs in six- sided prisms terminated by six- 
sided pyramids; specific gravity varying from 9*392 to 9*448; has an 
iron-black colour, with a metallic, semi-adamantine lustre, and yields a 
brown powder. (Breithaupt, J, pr, Chem., 10, 508.) The peroxide 
artificially prepared by (9) appears in brown six-sided tables, exhibiting 
a yellow lustre by reflection; that prepared by (1) forms delicate crys- 
talline scales, generally of a black reddish-brown colour when reduced 
to powder. Specific gravity of the artificial peroxide 8'903 (Herapath), 
8*933 (Karsten), 9*190 (P. Boollay). 

Flattner. Benelius. Thopison. Yau- 
Native, quelin. 

Pb 104 .... 86-67 86-2 86-51 80 79 

20 16 .... 13-33 13-8 13-49 20 21 

PbO" 120 .... 100-00 100-0 100-00 « 100 100 

Decompontions, 1. By light into oxygen gas and red lead; in a 
aimilar manner by gentle heating; by a stronger heat it is resolved into 
oxygen gaa and fused yellow protoxide.— 2. Oives up oxygen to many 



132 LEAD. 

substances^ sometimes with evolution of light and heat. When triturated 
with one-sixth of its weight of sulphur^ it sets fire to the sulphur, which 
burns with a brilliant flame, forming sulphide of lead. (Vauquelin, Ann, 
Chim. Ph^8. 62, 221); a mixture of 2 parts peroxide and I part sulphur 
takes firp whei^ touched with oil of vitriol; if the mixture likewise 
contains phosphorus, violent explosion takes place on trituration. 
(Grindei, Sckw» 15. 478.) With aqueous hypophosphorous acid, it forms 
phosphate of lead-oxide. (Wartz.) When immersed in sulphurous acid 
gas at ordinary temperatures, it becomes red-hot, and is converted into 
sulphate of lead-oxide (A. Vogel, Kastn. Arch. 4, 434); with aqueous 
sulphurous, acid it is likewise converted into sulphate of lead-oxide, very 
slowly at ordinary temperatures, more quickly with the aid of heat. 
Hyponitric acid dissolves it, forming a solution of nitrate of lead-oxide. 
With protochloride of tin it undergoes the same decomposition as red 
lead. (A. Vogel.) In nitrate of mercurous oxide it dissolves completely, 
forming nitrate of mercuric oxide and protoxide of lead. (LevoL)-^ 
When triturated with an equal weight of crystallized oxalic acid, it is 
decomposed without ignition, yielding vapour of water, carbonic acid 
gas, and carbonate of lead-oxide. It becomes incandescent when tritu- 
rated with one-eighth of its weight of racemio acid, tannin, or common 
sugar, or with one-sixth of tartaric acid, gallic acid, grape-sugar, or 
manna-sugar. ^Bottffer.) According to A. Vogel, it is likewise con- 
verted into leaa-oxlde by heating with oil of turpentine or solaiion of 
susar. — 3. By heated oil of vitriol it is converted into oxygen gas and 
sulphate of lead-oxide. — 4. By aqueous hypochlorous acid into oxygen 
gas (with a smaU quantity of chlorine) and chloride of lead. (Balard.) 
— 5. By aqueous hydrio^c, hydrobromic, hydrochloric or hydrooyanic 
acid, into water, iodide, bromide, chloride or cyanide of lead, and free 
iodine, bromine, chlorine, or cyanogen; e. g, 

PbCH + 2Ha = Pba + 2H0 + a. 

Conibinalions, — Peroxide of lead combines with many salifiable bases 
forming compounds in which it plays the part of an acid, and which may 
therefore be called SalU of Plumbic Acid, or Fhtmhaies, These compounds 
are formed by igniting the peroxide with salifiable bases. (Vid. FlumbcUs 
of Potash.) In accordance with this nomenclature, red lead may be 
called PlAimbate of Lead-oxide, (Fremy, QompU rend, 15, llOd; also y, 
J. Pharm. 3, 30.) 

Lead and Carbon. 

A. Carbide of Lead ? — a. By igniting tartrate or acetate ef lead-oxfde 
in a close vessel, a carbonaceous substance is obtained whieh takes fire 
in the air and leaves protoxide of lead. (Proust.)— 6. Cyanide of lead, or 
a finely divided mixture of charcoal and lead-oxide, yields on ignition a 
black powder, which takes fire in the air when heated, yielding globules 
of metallic lead. (Berzelius.) — c. Lead ignited with charcoal volatilizes 
and sublimes as a carbide in black spangles, having the metallic lustre. 
(John, Berl. Jahrb. 1820, 320.) 

B. Carbonate op Lead-oxide, or Lead Carbonate. — Carbonate of 
Lead. — ^Litharge slowly absorbs carbonic acid from the air. — a. Dicar- 
honaie, — Formed in the hydrated state by continued exposure of lead 
immersed in water to the open air. (DelavUle, N* OeM, 2, 682; BeoquereU 



LEAD-CARBONATE. 123 

Ann. Cfkim. Phyi, 54, 146; Yorke, Phil. Mag. J. 5, 82; Bonsdorff, Pogg^ 
40, 207.) If a pijQce of lead be left to tarnish in damp air, then scraped 
clean on one part, and covered with a layer of water 6 inches deep, the salt 
is deposited on the bright part of the metal in the form of an arboresci^nce 
consisting of crystalline scales. This compound may also be formed by 
keeping lead-oxide for a long time under water in a vessel exposed to the 
air; it then swells up, and is converted into white flakes, easily separated 
by washing from the unaltered oxide. (Bonsdorff, Pogg. 40^ 207.) Lead 
immersed in water containing -y^ pt. of potash becomes covered with a 
cmst of carbonate. (A. Vogel.) Finely granulated lead constantly 
stirred about in an aqueous solution of carbonate of potash exposed to 
the air, forms carbonate of lead-oxide, which may be removed from time 
to time by levigation. (Prechtl, J. pr. Chem. 2, 164.) The salt thus 
obtained is probably pure dicarbonate, unmixed with ordinary white 
lead. Possibly also the so-called white lead which Gannal and Versepuy 
{Compt rend. 16, 1327) obtained by agitating finely divided lead witn 
water, consisted of this salt. The dicarbonate when used as a pigment 
has not the coating power of white lead. (Bonsdorff.) After exposure 
to the air for some time, it effervesces more strongly with acids than 
before. Water dissolves but a trace of it. (Yorke.) 



\ 




Bonsdorff. 


Yorke. 


2PbO 


a\ .... o7*b5 •• 


86-51 


8900 


CO* 


22 .... 8-62 


y Jo .... 


7-66 


HO 


• V .... v'OO •• 


.•■... d Ow .... 


2-83 



2PbO,C02 + Aq 255 .... 10000 9999 .... 99*49 

h. Sesquibanc Carbonate. — White lead generally consists of this salt 
in the hydrated state. It is precipitated by carbonic acid from a solution 
of the acetate. — 1. New Mode of Preparation : Carbonic acid gas passed 
through a solution of basic acetate of lead-oxide takes up a portion of the 
oxide, and is precipitated with it in the form of white lead. The gas 
obtained by burning charcoal in a stream of air, or that which issues 
from apertures on the hill-side, as at Brohl, may be used for this pur- 
pose. When carbonic acid gas is passed in five separate portions through 
basic lead-acetate till the liquid becomes neutral, each of the Qve preci- 
pitates is found to consist of 2(PbO,CO») + PbO,HO. (Hochstetter.) 
a. French Method : proposed by Thenard, carried out by Roard. Dis- 
tilled vinegar or a solution of sugar-of-lead is saturated with litharge- 
carbonic acid gajs passed through it — the liquid poured off from the pre- 
cipitated white lead, and again saturated with litharge— carbonic acid gas 
again passed through it, — and so on. — b. English Method : introduced by 
Benson. 100 parts of finely ground litharge are stirred up to the con- 
sistence of paste with the aqueous solution of 1 part of sugar-of-lead-— 
the mixture introduced into a wooden receiver of peculiar construction — 
and there kept in constant agitation by means of grooved cylinders, at the 
same time that it is brought in contact with carbonic acid gas, generated 
by the combustion of coke, and cooled by passing through tubes immersed 
in water. When the paste, after a few days, ceases to absorb carbonic 
acid, it is ground with an additional quantity of water between mill- 
stones, and then levigated with water. The water dissolves out any ace- 
tate of copper or iron that may be present {Co7np. Schabarth, J. pr. Chem. 
*24, 328.) Since lead-oxide by itself absorbs carbonic acid very slowly 
|[and forms only the bibasic carbonate], the 100 parts of lead-oxide must 



124 LEAD* 

be gradually dbsolved by the 1 part of sugar-of-lead and conrerted into 
basio acetate, and then precipitated from the solation by combining with 
carbonic acid. (Pelouze.) 

2. Older Method of Freparation. — B^ exposing plates of lead to the 
vapoars of acetic acid, and at the same time to air loaded with carbonic 
acid. The predisposing affinity of the acetic acid for the lead-oxide 
induces the formation of that compound at the expense of the air ; the 
carbonic acid precipitates a portion of the lead-oxide from the basic ace- 
tate in the form of white lead ; the acetic acid, robbed of the greater 
portion of its oxide, then acts upon fresh portions of lead, &c &o. That 
the acetic acid, in this reaction, does not furnish the carbonic acid by any 
accidental decomposition, but that the latter must be introduced from 
some other source, and that the oxygen of the air is necessary for the 
oxidation of the lead, is shown by the following facts : Lead exposed to 
the vapours of acetic acid in air which is free from carbonic acid, yields 
nothing but acetate of lead. (Hochstetter.) A lead plate suspended 
within a vessel filled with oxygen and carbonic acid gas, and having a 
layer of acetic acid at bottom, produces a quantity of white lead, the 
oxygen and carbonic acid contained in which correspond to the quantities 
of those gases which disappear, but the acetic acid suffers scarcely any 
diminution. (Pelouze, Ann, Chim, Pkys. 79, 112; also c/. />r. Chem, 25, 
486.) Lead moistened with acetic acid, and exposed to carbonic acid 
gas free from air, at a temperature between 30° and 40% undergoes no 
alteration in the course of 24 hours ; but if air be admitted, the metal 
becomes coated with white lead in the course of six hours. (Hochstetter, 
J, pr. Chem. 26, 338.) In the Dutch method of preparation, weak beer- 
vineear is used containing only 1^ per cent, of acetic acid, and a consi- 
derable quantity of acetic acid is found in the resulting white lead ; 
hence the large quantity of carbonic acid contained in the white lead 
cannot be derived from the acetic acid. Formic acid in the place of 
acetic acid yields no white lead, because it does not form with lead-oxide 
a basic salt which can be decomposed by carbonic acid. (Pelouze.) 
a. DtUch Method : Earthen pots glazed insioe, 8 inches high, and some- 
what wider at top than at bottom, are filled to one-fourth of their depth 
with beer- vinegar : at one-third of their height from the bottom are three 
projecting points, on which a cross piece of wood is laid ; on this are 
placed, in a vertical position, a number of leaden plates rolled up in 
voluminous spirals; and the whole is covered with a leaden plate. The 
p<»ts are placed in rows upon horse-dung under a shed, and covered with 
boards, on which is laid another stratum of horse-dung; on this again is 
placed another row of pots, — and so on, till six rows are formed one above 
the other. The dung, by its slow decomposition, evolves heat, which 
favours the evaporation of the rinegar, and likewise gives off carbonic 
acid, whereby tue lead-oxide is separated from the acetic acid. Circula- 
tion of air is essential to this process • In the course of 4 or 5 weeks, 
the greater part or the whole of the lead is converted into white lead, the 
change taking place from without inwards. The white lead is then 
detached — ground to a semi-fluid consistence while still moist — ^freed 
from adhering acetate by washing — and dried in small round pots having 
the form of truncated cones. Unwashed white lead still contains a large 
quantity of neutral acetate (Pelouze); according to Hochstetter, it con- 
tains from 2 to 12 per cent.^6. German Method : Plates of 1^ are 
suspended within wooden boxes placed in heated chambers, and containing 



LEAD-CARBONATE. 125 

a stratam of acetic acid; or the plates are suspended in leated chambers^ 
having their floors covered with tan and acetic acid. 

When basic acetate of lead-oxide is precipitated by a verj slight 
excess of carbonate of soda, the precipitate likewise consists of 2(PbOy 
C0») + PbO,HO. (Hochstetter.) 

White lead forms a white, earthy, dense and heavy mass, which 
possesses greater coating power than any other white pigment. By 
whichever of the preceding methods it is prepared, it is founds when 
diffused through water and examined by the microscope, to consist of 
non-crystalline, transparent, round and oval globules of the size of 0*00001, 
or rarely from 0*00003 to 0*00004 of an inch; the new method yields 
globules somewhat larger and more transparent than those obtained by 
the older process. (Hochstetter.) 

I, a* M \b white lead prepared in the Magdeburg £Ekctory, by the 
newer French method. — 1, a. Hoch, is that prepared in the same manner 
on the small scale by Hochstetter. — 2, a. HM, is white lead from the 
Dutch factories, and prepared by the Dutch process. —2, a. Hoch, is white 
lead prepared by Hochstetter himself, according to the Dutch process. 
2| 6. Kr, is KrenMtr white (which contains more or less of a blue colour, 

f»robably indigo, and therefore yields a few metallic globules when ignited.) 
Mulder), — 2, 6. Off, is white lead from Offenbach.— ^n^^. is English 
white lead (mode of preparation not given).— ^arz. is white lead from a 
Victory in tne Harz (mode of preparation not given). — StraJt, is white 
lead prepared in a particular manner by Stratingh, containing less hydrated 
oxide than the ordinary product, and consequently remaining white in 
the dark when mixed with poppy oil. — Saturated, is Dutch white lead, 
suspended in water and exposed for some time to a stream of carbonic 

acid gas. 

Hochstetter. Mulder. 

ha,M. l,a.Hoeh. 2,b.Kr. 2,a.HoU, 2,b,Kr. 
3PbO 336 .... 86*38 .... 85*87 .... 86*20 .... 86*55 .... 86*59 .... 86*31 
2C0» 44 .... 11*31 .... 11*77 .... 11*45 .... 11*27 .... 1171 .... 11*35 
HO 9 .... 231 .... 2*14 .... 2*44 .... 2*21 .... 2*11 .... 2*16 

389 .... 100*00 .... 99*78 .... 100*09 .... 100*03 .... 100*41 .... 99*82 

Link. Hochstetter. Mulder. 

/ ^ X / \ . 

2, h, Kr, 2, b. Of. Harz, Engl, 2, a, HoU. Strut 

PbO .... .... 86*42 .... 86*16 .... 85*96 .... 86*2 

CO^ ^ 11*29 .... 11-28 .... 11*51 .... 11*91 .... 11*93 .... 12-35 

HO 2*23 .... 2*21 .... 223 .... 1*93 .... 1*93 .... 1*77 

100-16 .... 100-00 .... 99*82 .... 100*36 
Bette. Malder. Hochstetter. 

2, *. Kr, mUurattd, 2, a, Hoch. 2, b. Kr. 

PbO 85*25 .... 84*83 .... 84*21 .... 83*97 

CO* 12*65 .... 15*04 .... 14*73 .... 1503 

HO .... 0*59 .... 1*01 .... 084 

100-46 .... 99*95 .... 99*84 

Mnlder {Ann, Pharm. 33, 242; also J, pr, Chem, 19, 70) dried the white 
lead at 130° before analyzing it, whereby it lost from 0*23 to 0*34 per 
cent, of hygroscopic water. Hochstetter (J, pr, Chem. 26, 338) and 
Link {Ann. Pharm, 46, 232), and probably also Bette {Ann, Pharm. 
33, 251), analayzed white l«ftd dried at 1 00^— Hochstetter found in the 




126^ LB AD. 

Tarieties of white lead wbich be examined, a small quantity of acetate of 
lead- oxide, which was completelj extracted by boiling water, and which he 
regarded as the neutral acetate (sugar-of-lead). The proportion of 
acetic acid amounted to 0*56 per cent, in 1, a. M; to 0*52 in 2, b. Kr. upper 
series; to 0*34 in the Harz specimen, and to 0'70 per cent, in 2, 6. Kr, 
lower series. — Mulder found in Stratiugh's white lead: lead«oxidc 85*74; 
carbonic acid 12-22; combined water 1'75; hygroscopic water 0*55; and 
acetic acid 0'12 (excess 0*38). In the analyses given in the preceding 
table, the hygroscopic water is deducted together with the acetic acid, 
and as much lead-oxide as the latter requires to form neutral acetate. 
From other kinds of white-lead, Mulder could not extract any acetic acid 
by boiling with milk-of-lime, — the only substance thereby extracted 
being a trace of chloride of calcium, proceeding from chloride of lead 
contained in the white lead, and probably produced by impurities in the 
water used in preparing it. Link, also, on distilling Kremser-white with 
sulphuric acid, obtained not a trace of acetic acid. — Mulder, on dissolving 
white lead in cold and very dilute acetic acid, found that Dutch white 
lead left small quantities of lead, sulphide of lead, sulphate of lead-oxide, 
and chloride of lead — Kremser-white and English white lead, small quan- 
tities — and Stratingh's white lead, traces of sulphate of lead-oxide and 
chloride of lead. — [For the analyses of Ffaff and Bischoff^ vid. Schw, 53, 
119; J.pr. Chem. 7, 172.] 

From the analyses just given, it ma^ be concluded that white lead is 
composed of 2(PbO,CO*)4-FbO,HO, but that this compound — especially 
if the action of the carbonic acid be long continued — may be mixed more 
or less with monocarbonate, PbO,CO*, whereby its value is increased. 
The smaller the quantity of hydrate that it contains, the better docs it 
spread, and the less is it liable to turn brown; — e. g, that of Stratingh. — 
Probably, therefore, pure monocarbonate of lead-oxide, e, g. that prepared 
by precipitating a lead-salt with carbonate of potash, might be the best 
adapted for a pigment. 

Ordinary tokiU lead is mixed with considerable quantities of heavy 
spar, ffypsum or chalk. Heavy spar and gypsum, likewise any sulphate 
of lead that may be accidentally present, are left behind when the white 
lead is dissolved in dilute acetic or nitric acid. When white lead con- 
taining chalk is treated with hydrochloric acid, the filtrate evaporated, 
and the residue digested in alcohol, a solntion of chloride of calcium 
is obtained. Pure white lead dissolves completely in boiling dilate / 

potash-ley; concentrated solution of potash, according to Bottger, con- 
verts it into anhydrous lead-oxide. 

c. MonocarhonaU, — Found native in the form of Lead-spar or White 
lead-ore. Sometimes it exhibits the form of the sulphide or sulphate 
from which it has been formed. Obtained by precipitating a normal 
lead-salt with an alkaline carbonate in excess. Berzelius {Fogg. 47, 199) 
precipitates nitrate of lead-oxide with carbonate of ammonia; if carbonate 
of soda be used as the precipitant, and the precipitate boiled with the 
liquid, the carbonate of lead- oxide (according to the same authority) car- 
ries down with it a small quantity of carbonate of soda. Bette precipitates 
sugar-of-lead with carbonate of ammonia; Mulder with carbonate of 
potash. — ^ According to Lefort (H. J, Pharm, 15, 26), the precipitate 
thrown down by alkaline carbonates from> hot solution of lead consists 
of 3PbO,2CO,*HO; the neutral carbonate PbO,CO» is obtained only by 
precipitating in the cold. IT 



LEAD-CARBONATB. 127 

The native componnd belongs to the right prismatic system; Fig. 
155, 56, and other forms. m:w^=62** 56'; «:«=122** 28'; a:w=143''33'; 
t:<=144° 44'. Cleavage parallel to u. (Hauy.) Specific ir'-avity 6*465. 
(Mohs.) Harder than calcspar. Colourless, transparent, ^rith aii ada- 
mantine lustre. Decrepitates when heated. The artificially prepared 
salt is a white powder, whose density, according to Karsten, is 6*4277. — 
Carbonate of lead-oxide gives off carbonic acid when ignited; dissolves 
very sparingly in cold water, to a greater extent in water containing sal- 
ammoniac, especially on the application of heat. IT According to Frese- 
niuB {Ann, Fharm. 59, 124), 1 part of the salt dissolves in 50551 parts of 
pure water of medium temperature; in 23450 parts of water containing a 
small quantity of acetate of ammonia, together with carbonate of am- 
monia and free ammonia; and in a somewhat smaller quantity of water 
containing a large quantity of nitrate of ammonia together with carbonate 
of ammonia and free ammonia. 7 — It combines with chloride of lead. 

Klaproth. Bergmann. Berzeliof. Bette. 

naihfe, native. artificial, 

PbO 112 .... 83-58 .... 83-67 .... 83-51 .... 83-46 .... 83-49 

CO* 22 .... 16-42 .... 16-33 .... 16'49 .... 16-54 .... 16-00 

PbO,CO^.... 134 .... 100-00 .... 10000 .... 100-00 .... 100-00 .... 99'49 

Mulder. CheYreuL Proust. 

PbO 83-59 .... 83-64 .... 8385 

CO* 16-34 .... 16-36 .... 1615 



99-93 .... 100-00 .... 10000 

Lead-earUt is earthy monocarbonate of lead-oxide. — ZinC'lead-spar 
contains 7 per cent, of ^no-carbonate united with the lead-carbonate. 
(Karsten, Schw. 65, 365.) 

d. Fwe-fcmrtks Garhonaief — Mononitrate or acetate of lead- oxide 
mixed with sesquicarbonate of soda, yields, without sensible evolution of 
carbonic acid, a white, heavy precipitate, which, when washed and dried 
in the air, resembles white lead and contains 80 per cent, of lead-oxide 
and 20 of carbonic acid. 

e. Add Carbonate, — Carbonate of lead- oxide is very slightly solnble 
in water containing carbonic acid. A solution of lead -oxide in water is 
rendered turbid by a small quantity of carbonic acid, but regains its 
trassparency when treated with a larger quantity. (Wetzlar.) Lead 
covered with aqueous solution of carbonic acid, in a vessel containing air, 
begins to tarnish on the second day, and the liquid, which remains trans- 
parent, acquires a strong brown colour when treated with sulphuretted 
hydrogen, and yields a small white precipitate on boiling. But traces of 
various salts in the carbonic acid water prevent the solution of the lead. 
(Tiinnermann.) — The solution of lead-oxide in water is rendered turbid 
by a small quantity of carbonic acid, but regains its clearness almost 
entirely under the infiuence of a larger quantity. The mixture reddens 
litmus and becomes turbid when heated or when mixed with carbonate of 
soda. (Wetalar.) — White lead precipitated by carbonic acid from basic 
lead-acetate dissolves in carbonic acid water; the solution contains be- 
tween TTsVir ^^^ TTnnr ^^ oxide, is rendered turbid by monocarbonate and 
bicarbonate of potash, and coloured brown by sulphuretted hydrogen. 
(Yorke.) According to Fr. John {Ann, Fharm, 28, 117), carbonate of 
lead- oxide is not soluble in carbonic acid water. 



128 LEAD. 



Lead and Boron. 



Borate op Lead oxide, or Lead-borate.— <». By Fusion. — «. 112 
parts of lead-oxide fased with 24 parts of boracic acid form a very soft 
yellow glass, which has a density of 6*4, softens even on immersion in 
boiling oil, is a perfect insulator, and tarnishes in hydrosulpharic acid 
gas from formation of lead-snlphide. — ^. With 48 parts of boracic acid, 
the glass has less colonr and greater hardness. — y. With 72 parts of 
boracic acid, the glass is nearly colourless and as hard as flint glaas^ but 
has a greater refracting power. (Faraday, Pogg. 18, 561.) 

6. By Precipitation, An aqueous solution of borax added to a lead- 
salt throws down white flakes, which may be fused to a transparent glass; 
they are slightly soluble in pure water, but insoluble in water containing 
a soda-salt; hence borax in excess throws down the whole of the lead 
from lead-salts. (Soubeiran.) The salt precipitated by borax is PbO,2BO^ 
and the same proportion holds good in precipitation by qnadroborate of 
ammonia, because, in that case, boracic acid remains in the liquid in com- 
bination with a very small quantity of lead-oxide. (Soubeiran, «7. Pharm, 
11, 31.) According to TUnnermann {Ka^tn, Arch, 20, 8), borax added in 
excess to nitrate of lead-oxide, either at ordinary temperatures or at a 
boiling heat, throws down a salt containing 70*99 p. c. lead-oxide to 
2 9 '01 boracic acid. If the solution of borax is previously mixed with a 
quantity of boracic acid sufficient to give it a slightly acid reaction, a 
bulky white precipitate is thrown down containing 55*18 lead-oxide to 
44*82 boracic acio. 



Lead and Phosphorits. 



A. Phosphide op Lead. — a. When phosphorus is thrown upon melted 
lead, or when lead-filings are ignited with an equal weight of glacial 
phosphoric aoid, or chloride of lead with phosphorus, a compound is 
formed containing not more than 15 per cent, of phosphoms: it has the 
colour of lead; may be cut with a knife, but splits into laminn when 
hammered; tarnishes quickly when exposed to the air; and, when heated 
before the blowpipe, yields a phosphorus-flame and a globule of lead. 
(Pelletier, Ann. Chim, 13, 114.) — b, Phosphuretted hydrogen gas passed 
for two hours through a solution of sugar-of-lead, yields a brown preci- 
pitate, which bums before the blowpipe with a small phosphorus-name, 
forming beautifully crystalliied lead-phosphate. (H. Rose, Pogg, 24, 
326.) 

B. Htpophosphitb op Lead-oxide, or Lbad-hypophosphite. — 
1. Lead-oxide in excess yields with cold aqueous hypophosphorous acid a 
solution which exhibits an alkaline reaction, and, when neutralized with 
hypophosphorous aeid, deposits the monobasic salt in crystalline lamina) 
having a feebly acid reaction. When the acid is heated with excess of 
oxide, lead is reduced and phosphate of lead-oxide formed. (H. Rose, 
P(^g. 12, 288). — 2. By digesting recently precipitated carbonate of lead« 
oxide with aqueous hypophosphorous acid, and then filtering and eva- 
porating, small, slightly rhombic prisms with dihedral summits are 
obtained, which redden litmos and give off no water at 100°. (Warts, 
Ann. Pharm. 43, 227.) 



LEAD-PHOSPHITE. 129 

Cry9tdUixed. Wurtz. 

PbO 1120 .... 66-12 6605 

PO 39-4 .... 23-25 23-15 

2HO 18*0 .... 10-63 10-80 

PbO,PO + 2Aq 169*4 .... 10000 10000 

When heated to redness in a retort^ it gives off spontaneously in- 
flammable phosphnretted hydrogen^ and leaves phosphate of lead-oxide 
mixed with a very small quantity of phosphoric oxide. Dissolves with 
difficulty in cold water, more easily in hot water, but not in alcohol, 
which, on the contrary, precipitates it from the aqueous solution in pearly 
scales. The aqueous solution is not decomposed by boiling. Ammonia 
in excess throws down from it a powder containing 91*29 per cent, of 
lead-oxide, 1-57 acid, and 7*14 water; when the liquid filtered from this 
precipitate is boiled, it deposits flakes which, after drying, contain 86*83 
oxide, 4-58 acid, and 8*79 water; the liquid still retains lead-oxide in 
solution* (H. Rose.) 

The alkaline liquid obtained by saturating aqueous hypophosphorous 
acid with lead-oxide, if kept cold (or a long time in a stoppered bottle, 
deposits a sandy powder, and acquires thereby the power of reddening 
litmus; because the salt which remains in solution is monobasic. (H. Rose.) 
— Wurtz did not succeed in preparins^ a basic salt; the alkaline hypo- 
phosphites do not precipitate basic lead-acetate; but the mixture becomes 
turbid even in the cold, and more quickly when heated, giving off pure 
hydrogen gas and depositing phosphite of lead-oxide, which is likewise 
the sandy powder observed by H. Rose. — A peculiar compound belonging 
to this head was obtained by Grotthuss. {Fhys. ckem, For9chungen,.lf 
106.) 

C. Phosphite op Lead-oxide, or Lead Phosphite. — a. Quadrohasic. 
— ^Formed by digesting recently precipitated diphosphite of lead-oxide 
with aqueous ammonia in a closed vessel for several weeks, and then 
washing with alcohol. The filtrate is free from oxide of lead. The salt 
when heated to redness in a retort, turns black and yields hydrogen gas 
free from phosphorus, and a residue which in 100 parts contains 87*03 
oxide and 12*97 phosphoric acid. 100 parts of the salt evaporated with 
nitric acid and then heated to redness, leave 99*92 parts of lead-phosphate 
containing 85*80 parts of oxide. (H. Rose, Fogg. 9, 222.) 











H. Rose. 


4PbO 


4480 


• ••• 


85*92 


85-81 


PO» 


55*4 


§••• 


10-63 


10-95 


2HO 


180 


• ••• 


3*45 


3-24 


4PbO,PO» + 2Aq. 


521-4 


«••• 


10000 


10000 



b, Bibagic, — To prepare this salt, terohloride of phosphorus dissolved 
in a large quantity of water is neutralized almost completely with 
ammonia; a hot aqueous solution of lead-chloride added to the liquid, the 
bulky precipitate freed from adhering lead-chloride by continued washing 
with boiling water; then pressed to remove the greater quantity of the 
liquid, and dried in vacuo over oil of vitriol. — White powder. (Berzelius.) 
Even if the washing be continued till the wash- water no longer gives a 
turbidity with solution of silver, the precipitate still retains a portion of 
lead-chloride; hence a better mode of preparation is to precipitate acetate 
of lead-oxide with phosphite of ammonia. (H. Rose, Pogg, 9, 42.) 
VOL. v. K 



laO LBID. 



2PbO 


224'0 


• •»• 


77-67 

19-21 

3-12 


Benetiu. 
77-69 


PO» 


55-4 


1916 


HO 


■•••■••••«■• flf w 


3-15 



2PbO,PO» + Aq 288-4 .... 100-00 10000 

The aalti wlien heated in a retorti turns blacky givec off hydrogen gas 
together with a large qnantity of non-spontaneouslj inflammable phos* 
phnretted hydrogen, and afterwards yields pare hydrogen gas together 
with a tolerably large quantity of sublimed phosphorus — ^more than any 
other phosphite — ^and leaves a blackish residue. Since the salt prepared 
with coloride of lead likewise yields this blackish residue, the blackening 
probably arises, not from the acetic acid of the lead-acetate, but from the 
phosphorns; hence on dissolying in nitric acid, the black matter which 
separates at first is gradually dissolved. The blackish residue contains 
7901 per oent. (5 At.) lead-oxide and 20-99 per cent, (not quite 2 At) 
phosphoric acid. Therefore : 

6(2PbO, P0» + HO) = lOPbO, 4P0* + P + 5H- 

(H. Rose, Pog^. 9, 221.) — The salt evolves sulphurous acid from heated 
oil of vitriol. (Wurti.J When heated with nitric acid, it yields diphos- 
phate of lead-oxide, wnereas cold nitric acid dissolves it without alteration. 
(Berzelius, Ann, Chem. Phys, 2, 229.) — It dissolves very sparingly in 
warm phosphorous acid, aud is precipitated from the solution in white 
flakes by ammonia. (Wurtz.) 

D. Ordinary Phosphate op Lbad-oxids, or Lead-phosphatc. — 
a. Terhasic, 1. By digesting b with aqueous ammonia. — 2. By precipi- 
tating neutral acetate of leiul-oxide with diphosphate of soda^ whereby 
acetic acid is set free. White; less fusible than b. When heated on 
charcoal before the blowpipe, it is reduced to 6, while the third atom of 
lead-oxide is reduced. (Berzelius^ Mitscherlich, Heintz.) 

SPbO 336-0 

cPO* 71-4 





Berzelius. 


8J-47 


82-52 


17-53 


17-48 



3Pb0,cP0« 407 '4 .... 10000 10000 

h, Pvbcuic. Formed by double decomposition. — The best mode of 
obtaining it pure is to mix diphosphate of soda with a hot aqueous 
solution of chloride of lead. (Berzelius.) The alkaline diphosphate must 
be added drop by drop to the lead-salt, so that the latter may remain in 
excess: in the contrary case, a monophosphate of the alkali is formed and 
triphosphate of lead-oxide is precipitated. (Mitscherlich.) The salt is 
obtained in an impure state by mixing acetate or nitrate of lead-oxide 
with an aqueous solution of acid phosphate of lime, or with a solution of 
bone-ash in nitric a<Md, or with urine. -^ White powder, which fuses at a 
gentle heat, and on cooling assumes a crystalline structure, the solidifica- 
tion bdng accompanied by vivid incandesoenee. (Fuchs, Sehw. 18, 292.) 

2PbO 2240 .... 75-83 

P0» 71-4 .... 24-17 



Berselios. 


Berthisr. 


Thomson. 


76 


... 77-5 .. 


80 


24 


• •• ^A w •• 


20 



2PbO,PO».... 295'4 .... 10000 100 1000 „. 100 



LEAD-PHOSPHATB. 181 

The salt mfilia before the blowpipe on charooal, wiilMwt rednetiot of 
the lead. (H. Rose^ When strongly ignited with chareoal, it yields 
lead and likewise pnosphorus which volatilizes. {Sch. 83.) It is deeom- 
posed by sulpharic and by hydrochloric acid; dissolyes in nitric acid, and 
in potash and soda, not in water or in acetic acid; bnt according to Brett^ 
it dissolves in solution of sal-ammoniac, and is completely precipitated 
therefrom by a large excess of ammonia. 

T According to Heintz {Pogg, 73, 122), and Gerhardt {N. Ann. 
Ckim. Pkys. 22, 505), the precipitate obtained by mixing solutions 
of chloride of lead and phosphate of soda always contains chlorine; 
it is in fact a double salt of phosphate and cnloride of lead {vid. 
p. 150). — ^When nitrate of lead-oxide and ordinary phosphate of soda 
are mixed, a precipitate is formed consisting of two salts, one of 
which contains 3 At. base to 1 At. acid, and the other 2 At base and 
I At. water to 1 At. acid. The salt containing 2 At. lead-oxide can only 
be obtained pure by precipitating a boiling solution of lead-nitrate with 
pure phosphoric acid. The precipitate is white, crystalline, and has a 
mother-of-pearl lustre. It fuses before the blowpipe. Its analysis agrees 
with the formula, 2PbO,HO,PO«. (Heintz.) T 

c. 3 At. Acid to 4 At. Base, — By precipitating the hot aqueous 
solution of lead-chloride with excess of monophosphate of soda, and 
washing with hot water. White powder which reddens litmus, (Berzelitts.) 
Probably a mixture of bibasic and monobasic salt. 

Igmted. Beradnis. 

4FbO 448-0 .... 6766 69*731 

3P(y 214-2 .... 32-34 30269 

4PbO,3PO* 662*2 .... 100-00 ZIZ 100-000 

d. With excess of Acid. — Lead dissolves slowly in aqueous phosphoric 
acid, when aided by the action of the air; a, 6, and c dissolve sparingly in 
that acid; the solution when evaporated yields a few homy crystals. 
[On the phosphates of lead-oxide, vid, Ann. Pharm, 68, 286j also Gerhardt, N. Ajmu 
Chim. Phyt. 22, 505; Ueint2, Pogff. 73, 122.] 

E. Pyrophosphate op Lead-oxide. — By precipitating a lead-salt 
with dip3rrophosphate of soda. The precipitate dissolves in an excess of 
that reagent, and when boiled with ordinary diphosphate of soda, it ia 
converted into ordinary phosphate of lead-oxide and pyrophosphate of 
soda. (Stromeyer) — IT White amorphous powder soluble in nitric acid, 
in caustic potash^ and in pyrophosphate of soda — ^insoluble in ammonia^ 
acetic acid, and sulphurous acid. (Schwarzenberg.) 

SchwAAenberg. 

2PbO 224-0 .... 75-83 76-29 

ftPO* 71-4 .... 24-17 83-71 

2PbO,iP0* 295-4 .... 10000 10000 

According to Gerhardt (N. Ann. Chim. Phys. 23, 505), the preeh>itate 
formed by mixing an alkaline pyrophosphate with excess of lead-nftrate^ 
consists of 2PbO,PO*; but, on the contrary, if the alkaline pyrophosphate 
is in excess, the precipitate is redissolved on the application of neat, and 
after it has become permanent, contains variable quantities of alkali. A 
definite compound, PbO,NaO,PO^ in the form of a granular precipitate 
insoluble in water, may be obtained by boiling the first-mentioned preci<' 
pitate with excess of pjnrophosphate of soda. T 

k2 



134 LBAD. 

disnlpUde and aftenrai*di ond-foartb tnlphide of lead. (Foarnet.) Hy- 
drogen gae, at a somewhat powerfal red heat, conrerts Bulphide of lead 
into salpharetted hydrogen and metallic lead. (Descotils.) H. Rose, who 
at DesootilB* enggestion applied less heat, obtained no decomposition. 
2 parts of sulphide of lead ignited in a porcelain retort wiUi 1 part of 
carbonate of soda yield 53 per cent, of lead, together with an easily fusible 
slag^ containing snlpfaide of lead^ sulphide of sodium, and a large quantity 
of sulphate of lead-oxide : 

7PbS + 4NaO -= NaO, SO^ + 3(NaS, PbS) + 4Pb. 

The same mixture ignited in an open crucible yields 63 per cent.; and if 
heated in a shallow ressel, the heat being slowly raised and long con- 
tinued, it yields from 75 to 80 per cent.; for the oxide which forms by 
contact with the air, exerts a decomposing action on the sulphide of lead 
which still remains dissolved in the sulphide of sodium, — and if 4 parts 
of dry carbonate of soda be used to 1 part of lead-sulphide, the separation 
of the lead is complete. The action of the air may be replaced by that 
of nitre. If 10 parts of galena be fused with 30 parts of <»,rbonate of 
soda, and 3 parts of nitre added, the quantity of lead reduced amounts to 
between 75 and 78 per cent. The galena may likewise be fused with 
carbonate of soda and nitre at once. 1 part of sulphide of lead fused 
with 4 parts of black flux yields 75 parts, and with 4 parts of tartar, 
80 per cent, of lead; and 1 pt. lead-sulphide ignited in a charcoal crucible 
with 3 or 4 parts of carbonate of soda yield from 74 to 75 per cent, of 
metal. Lime or baryta, heated to whiteness with sulphide of lead in a 
charcoal crucible, decomposes it partially, so that the slag of sulphide of 
lead and barium or sulphide of lead and calcium contains globules of lead 
mixed with it. (Berthier^ Ann, Ckim. Fhys. 33, 156.) Frotosalphide 
and protoxide of lead decompose one another without fusion. With 1 
atom of sulphide and 2 atoms of litharge, the products are sulphurous 
acid gas and metallic lead : 

PbS + 2PbO = 3Pb + S02. 

Any excess of litharge remains undecomposed on the top of the lead; if 
an excess of sulphide be present, a lower sulphide is formed. Bat if the 
litharge already contains another metallic sulphide in solution, e. g, sul- 
phide of zinc or sulphide of iron, it then dissolves the lea(^-sulphide 
without decomposing it. (Berthier, Ann, Chim, Phys. 39, 262.) Ac- 
cording to D'obereiner (Schw. 17, 248), sulphide of lead maybe fused with 
the protoxide without aecomposition. Protosulphide of lead ignited with 
protoxide of copper, yields sulphurous acid, metallic copper, and a slag 
consisting of dioxide of copper and protoxide of lead. (Karsten, S<^w, 
66, 400.) — Iron separates lead from the sulphide almost entirely, even 
when the sulphide is dissolved in sulphicle of sodium. 10 parts of 
sulphide of lead, 20 of dry carbonate of soda, and 2 or 3 of iron, yield 
from 77 to 80 per cent, of lead. (Berthier.) Recently precipitated 
sulphide of lead added to the aqueous solution of a copper or silver salt 
throws down sulphide of copper or sulphide of silver. (Anthon.) Sulphide 
of lead is not decomposed by aqueous sulphurous acid, nor, at a red heat, 
by carbonic oxide or carbonic acid gas. 

D. Pentasulphide of Lead. — Lead-salts give with aqueous penta- 
sulphide of potassiiim a brown-red precipitate, which, in a few seconds, is 
resolved into a mixture of protosulphide of lead and free sulphur. 
(Berzelius.) 



H7P0SULPHATB Of LEAD-OXIDE* 136 

E. HTPOiVLPHiTE OF Lbad-oicyds. — Formed by precipitating nitrate 
of lead-oxide with hyposulphite of lime. — ^White powder^ which blackens 
CTcn below 100°. When raised to a higher temperature, out of contact 
of air, it gires off snlphurous acid gas, and is converted into sulphide of 
lead mixed with solphate; when heated in contact with air, it burns with 
a feeble flame. It dissolyes in 3266 parts of water. (Herschel.) Remains 
white at 100^, but acquires a dark colour at 200°. When heated in a 
retort, it yields sulphur, sulphurous acid, and 78*57 per cent, of a grey 
pulverulent mixture of sulphide of lead and sulphate of lead-oxide. It 
dissolves in aqueous alkaline hyposulphiteSi forming doable salts. (Ram- 
melsberg, Fogg, 56, 308.) 

Herschel. RammelBberg. 

PbO 112 .... 70 70-3 69-34 

SK)» 48 .... 80 



PbO,S^O' 160 .... 100 



NM 



F. Tbtrathionatb of Lead-oxidb.*— Iodine added to aqneons hypo- 
snlphite of lead-oxide throws down iodide of lead, while tetrathionate of 
lead-oxide and a trace of iodide of lead remain in solntion. (Fordos & 
Q^lis.) 

G. Trithionate or Lead-oxidb. — Aqaeoos trithionic acid foniui 
with lead-salte a white precipitate which turns black when heated* 
(Langlois.) 

H. Sulphite of Lbad-oxidb, or Lbad-sulphite. — Formed by double 
decomposition. White, tasteless powder, Oives off sulphurous acid gas 
when heated, and .leaves a mixture of sulphide and salphate. Strong 
nitric acid converts it into sulphate. Sulphuric or hyorocUorio acid 
expels sulphurous acid from it. insoluble in water. 

Gaj-Losste. Tlomaon. 

PbO 112 1... 77'7T T8 745 

SO» 32 .... 22-22 22 26-5 

PbO,SO« 144 .... 10000 ZZ 100 TZi! 1000 

I. Htposulphatb of Lead-oxide. — a, Tenhasic Salt, — Formed by 
decomposing 6 or e with excess of ammonia. Soft, white powder, having 
an alkaline reaction, containing about 81 parts (10 At.) of lead-oxide, 
5 pts. (1 At.) of acid, and 14 pts. (20 At.) of water; decomposed by 
carbonic acid; very sparingly soluble in water. 

b. Bibasie f — By decomposing the solution of c with an insufficient 
quantity of ammonia. Very soft, white needles, having an alkaline 
reaction. When digested with nitric acid, this compound is converted 
into 85 '09 per cent, of sulphate; and, if sulphuric acid be then added to 
the liquid, 11 per cent, more of sulphate is precipitated. It gives up its 
excess of lead-oxide to the carbonic acid of the air. Difficultly soluble in 
water. 

€. Monobfuie, — Carbonate of lead-oxide is dissolved at a gentle heat 
in aqueous hyposnlphuric acid, and the solution left to spontaneous 
evaporation. Large crystals, permanent in the air; they belong to the 
hexagonal system, and are nearly identical in form with those of the 
hyposulphates of strontia and lime. Primary form. Fig, 1 5 1 ; r' : r*= 1 1 9**. 
Taste, very sweet and somewhat rough. The salt when ignited yields 
99^86 per cent, of lead-snlphate. Very easily soluble in water. (Heeren.) 



136 . LEAD* 

Cfrf$taUiged, Heeren. 

PbO 112 .... 50-91 51-04 

S»0» 72 .... 32-73 33-01 

4HO 36 .... 16-36 15-95 

PbO,S*0* + 4Aq. 220 .... 100-00 ZZ 10000 

K* Sulphate of Lead-oxide, or Lead-sulphate. — a. Basic, — 
1. AqueonB ammonia digested with salt, h. removes only a part of the 
sulpharic acid. (Vanqueliii, Scker. J, 4, 56.) — 2. Monosiuphate of lead- 
oxide is rendered much more fusible by the addition of more oxide. One 
atom of lead-oxide forms with 1 atom of the sulphate, a colourless, easily 
fusible mixture, which, on cooling, crystallizes in transparent and colour- 
less prisms; with 2 atoms of the sulphate, it fuses at commencing white- 
ness and yields a fibrous enamel; with 4 or 8 atoms of the sulphate, a 
whitO) translucent, somewhat crystalline glass is formed. (Berthier, Ann, 
Chim. Fhys. 43, 287.) 

h. Monobasic. — Found native, in the form of Lead-vitriol. Some 
specimens of the native sulphate, formed from galena, are still cleavable 
in the direction of the cubical faces. — This salt is formed: 1. When oil of 
vitriol is heated with lead. — 2. Slowly, when lead is placed in contact 
with aqueous sulphuric acid and with the air. — 3. By contact of sul- 
phuric acid with lead-oxide or its salts. — 4. By contact of sulphuric 
acid with red or brown peroxide of lead. Lead-oxide does not absorb 
the vapour of anhydrous sulphuric acid at ordinary temperatures. (H. 
Rose, Fogg. 32, 94.) — Kuhlman {Ann. Pharm. 38, 366) observed that 
when the acid vapours in a vitriol- work were made to pass from the first 
leaden chamber into several others, in order to condense the whole of the 
sulphuric acid, the leaden plates were rapidly corroded by the excess of 
hyponitric acid present, and sulphate of lead-oxide was formed in the 
shape of silky needles and laminae, of specific gravity 6*07. 

The native sulphate belongs to the right prismatic system; Fig. 46, 
47, and other forms, produced more especially by the entry of the faces 
u, m, and t. Cleavage parallel to i, y, and u; i : i'=76° 12'; y : y'= 
101^*32'; i : y=119° 51' (Hauy) u : tt = 104°; the angles exactly equal 
to those of CcBlestine. (Mitscherlich.) Specific gravity 6*1691 (Karsten); 
6*298 (Mohs). Hardness equal to that of calcspar. Transparent, colour- 
less, with an adamantine lustre. — The artificial variety forms a white, 
loosely coherent mass, or a white, powder. — Fuses at a red heat and 
forms a crystalline solid on cooling. 

Klaprotb. Berzelius. Berthier. Buchols. 

PbO 112 .... 73*684 .... 73-5 .... 73-615 .... 73-99 .... 74 

SCy 40 .... 26316 .... 26-5 .... 26*385 .... 26*01 .... 26 

PbO,S08 152 .... 100-000 .... 1000 .... 100-000 .... 100*00 .... 100 

Not decomposed at the highest temperature when heated alone. 
When ignited with silica or clay, it gives off all its acid in the form of 
sulphurous acid and oxvgeu gas. Heated to redness with 68 per cent, of 
lead or 0-3 of charcoal, it yields pure vitrefied oxide; with 6 per cent, 
of charcoal at the same temperature, it yields 63 per cent, of metallic 
lead, on the surface of which a small quantity of fused oxide floats; with 
9 per cent, of charcoal,! sulphurous acid is evolved, and 71 per cent- 
of lead containing sulphur (67 lead to 4 sulphur) produced. (Ber- 
thier, Ann. Chim. Phys. 20, 275.) When lead-sulphate is heated to low 
redneas with excess of charcoal, carbonic acid is evolved without any 



}■ 



LfiAD-SULPHATE. 137 

salphuroQB aeid, and snlpbide of lead remains behind; with equal num- 
bers of atoms (152 lead^ 6 charcoal) also, proyided the temperature be 
kept low^ nothing but carbonic acid is evolved, and only half of the salt 
is reduced to the state of sulphide: 

2(PbO, S0») + 2C =1 PbO, SC + PbS + 2C0«. 

If the heat be then raised, the sulphide and sulphate decompose each 
other, forming sulphurous acid and metallic lead: 

PbO, SO" + PbS = 2Pb + 2S0' 

With 2 atoms of lead-sulphate to 1 atom of charcoal (304 lead, 6 char« 
coal), i at. sulphide of lead is produced at a moderate red heat: 

4(PbO,SO») + 2C - 3(PbO,SO") + PbS + 2CO'. 

at a stronger red heat, this half-atom of sulphide, together with 1^ at. 
sulphate, yields sulphurous acid gas and protoxide of lead: 

3(PbO,SO") + PbS = 4PbO + 4S0«. 

(Gay-Lussao, Ann, Chim, Pkys, 63, 454; also J, pr. Chem. 11, 68.)— 
Sulphate of lead-oxide ignited in a current of hydrogen gas yields water, 
sulphurous acid, and finally hydrosulphuric acid, whilst a mixture of 
metallic lead and sulphide of lead is left behind. (Arfved8on,Po^^. 1,73.) 
•»When fused with an equal number of atoms of common salt, it gives 
off dense fumes of chloride of lead, and yields a compact grey mass with 
a scaly fracture. With ^ At....l At. chloride of barium, it fuses imper- 
fectly, giving off chloride of lead, and forming a white enamel with a 
granular fracture. (Berthier.) — By aqueous carbonate of ammonia or 
carbonate of potash, it is converted into carbonate of lead-oxide. — It 
dissolves completely in warm ammonia, and separates from the solution 
[as a basic salt)] on cooling. (Wittstein.) It is slightly decomposed by 
a cold solution of sal-ammoniac, to a greater extent on ooiling, and com- 
pletely, when repeatedly boiled with fresh quantities of sal-ammoniac, 
the products being chloride of lead which crystallizes on cooling, and 
sulphate of ammonia. (A. Vogel, J. pr. Chem, 2, 196.) It dissolves 
completely in a boiling solution of hydrochlorate or succinate of ammonia, 
but does not separate out on cooling. (Wittstein, Repert. 63, 320.) The 
solution in cold sal-ammoniac is precipitated by a very large excess of 
ammonia. (Brett.) — By solution of common salt, it is but very slightly 
decomposed. (Bley, N. Tr, 26, 2, 292.) — It dissolves in 969 parts of 
aqueous nitrate of ammonia of specific gravity 1*29. The solution is 
rendered turbid by sulphate of potash, not by sulphuric acid, because the 
latter sets nitric acid free, which then exerts a still stronger solvent 
action. — It dissolves in 47 parts of aqueous acetate of ammonia, of specific 
gravity 1 '36, forming a solution which is precipitated by sulphuric acid 
and sulphate of potash. (Bischof, Schw, 51, 228.) — When digested with 
aqueous nitrate of baryta containing excess of acid, it yields nitrate of 
lead oxide. (Th6nard.) — It dissolves slightly in heated hydrochloric acid, 
the solution depositing a small quantity of chloride of lead on cooling, 
while free sulphuric acid remains in the liquid. (Descotils, N. Gehl. 2, 
175.) — On evaporating the hydrochloric acid solution (but not on boiling), 
the chloride of lead is decomposed. (Hayes.) — Sulphate of lead-oxide 
dissolves in nitric acid, the more readily in proportion as the acid is 
warmer and more concentrated. At 12*5'', it dissolves in 172 parts of 



138 lead; 

nitric Acid of speoifio gravity 1*144. Water doee not render the eolation 
turbid, but sulphuric acid preoipitatet it oompletelj; it is likewiee 
precipitated by carbonate of ammonia. (Bischof.) Dilute nitric acid 
also dissolves it, though slowly; the solution is not precipitated by 
phosphoric or hydrochloric acid, and not at all, or but very slightly, by 
alkaline sulphate's; it is precipitated, however, by tartaric acid, and more 
especially by dilute sulphuric acid : the larger the excess of nitric aoid 
present, the greater is the quantity of sulphurio acid required to produce 
a precipitate. The precipitation is gradual, and if the quantity of nitric 
acid be not too great, almost complete. (Waokenroder, Ann, Fkarm, 41^ 
319.) The solution of lead-sulphate in nitric acid yields^ on evaporation, 
delicate needles of sulphate, and likewise octohedrons of the nitrate. 
(Kobell, Kastn. Arch. 5, 93.) — Oil of vitriol dissolves sulphate of lead- 
oxide more abundantly than dilute sulphuric acid; but, according to 
Hayes, the ordinary oil of vitriol of commerce dissolves a greater Quantity 
than a more concentrated acid. Water separates the salt from the solu- 
tion, the more completely as the dilution is carried to a greater extent, 
so that ultimately only a trace remains in solution. — IT Dupasquier 
{J. pr. Chem. 31,417) found that sulphuretted hydrogen produced no 
precipitate in strong sulphuric acid which had been boiled with recently 
precipitated lead-sulphate ; but when the acid was diluted with water, 
the sulphate was precipitated, and then exhibited the usual reaction with 
sulphuretted hydrogen; the effect produced by water is of course equally 
produced by any stronger base. IT According to Hayes {^SiU» Amer. J. 
17, 195), the cold solution of lead-sulphate in strong sulphnric acid, is 
also rendered turbid and precipitated by hydrochloric acid, because the 
chloride of lead which it forms is insoluble in cold oil of vitriol ; but the 
precipitate disappears on heating. — In pure water, sulphate of lead-oxide 
IS less soluble than sulphate of strontia, but more soluble than sulphate 
of baryta. IT According to Fresenius (^Ann. Pharm. 59, 125), 1 part of 
iead-sulphate dissolves m 22816 parts of pure water at 11^ C, and in 
86504 parts of dilute sulphuric acid. IT 

L. Sulphate and Carbonate of Lbad-oxidb. — a. LeadkUlUe.'^ 
(3PbO,CO'),-hPbO,SO^ — Yellowish or greenish white rhombic prisms, 
the angles of the lateral edges being equal to 107° dO' and 72*^ dCr. 6p. 
gr.=6-3. . 6-5. (Brooke.)— 6. ZanarWs.— PbO, 00*+ PbO,SO*.— Greenish 
or yelloivish white acute rhombohedrons and sixnrided prisms, of specific 
gravity 6*8 — ^7*0; effervesces slightly with nitric acid. (Brooke.) 



arpbo.co*^ 


LeadhiUite, 
402 .... 72-66 
152 .... 27-44 




Stromey 
72-7 
27-3 


er. 


Thomson. 
72-57 


PbO,SO» 


27-43 




• 


PbO, C0« 
PbO, so» 


554 


.... 10000 

LanarHie, 
194 .... 46-85 
152 .... 5S15 


100-0 


Thomson. 
46-04 
53'»6 


10000 






286 .... 


10000 




100-00 





M. SuLPHOCARBONATB OF Lead. — Accordiug to Berzellus, lead-salts 
give a dark brown precipitate with sulphocarbonate of calcium, and, 
according to Zeise, a red precipitate with sulphocarbonate of ammonium. 
The deep yellow, supernatant liquid becomes colourless in the course of 
24 hours. (Berzellus.) The precipitate is black after drying, takes a 



LEAD AND SELENIUM. 130 

poUflh by preflsare, and when distilled, giroB off blflolphide ai oarbon^ and 
ifl eonyerted into sulphide of lead. (Berselius.) The precipitate is 
decomposed in a few boars nnder water at ordinary terapemtnres, and 
more slowly ander alcohol, jrielding sulphide of lead and bisulphide of 
carbon, whereby its red eolonr ie changed to blaek. If it be quickly 
dried in vacuo over oil of vitriol, and then heated, sulphide of carbon 
sublimes in drops, and sulphide of lead remains behind. Cold hydro- 
sulphate of ammonia and heated potash-ley instantly blacken the red 
precipitate by withdrawing the sulphide of carbon. Iodine, nitric acid, 
and oil of vitriol produce no change in the compound at ordinary tempe« 
ratures. 

Lead and Selenium. 

A. Selenide of Lead. — ^Found as a mast closely resembling galena. 
Sp. gr. 6*8. (Comp. Ziuken, H. Rose, Pog^, 3, 274, and 286.) — Lead and 
selenium combine, with evolution of light and heat, and form a grey, 
porous, soft mass, which becomes silver-white by burnishing. The com- 
pound when ignited in open vessels, evolves without fusion (the native 
selenide with decrepitation), first a small quantity of selenium, and after- 
wards of selenide of lead in white fumes. When roasted on charcoal 
before the blowpipe, it imparts a blue colour to the flame, gives off 
selenium, produces a red, yellow, and white deposit on the charcoal, and 
is gradually converted into basic selenite of lead -oxide, which imm^ 
d lately sinks into the charcoal, leaving a silvery film of reduced selenide 
of lead. — Cold nitric acid dissolves the lead, depositing red selenium^ 
which, on the application of heat, dissolves in the form of selenious acid. 
(Berzelius.) The powder yields with oil of vitriol, first a brownish, then 
a greenish^ and then a red-brown mixture. If water be added while the 
mixture is greenish, the colour changes to a beautiful red. (Zinken, 
iT. Tr. 12, 2, 278.)— A small quantity of selenium mixed with lead^ 
renders it whiter, less ductile, and less nisible. (Berzelius.) 











H. Rose. 


Stromeyer. 










Tilkerode. 


Clautthal, 


Pb 


104 


• !■• 


72-72 


71-81 


70-98 


Se 


40 


«•«• 


27-28 


27-59 


28-11 


Co 


• 


• ••• 


• ■ 


■•#••• ■>• 


•..•• u'OiS 


PbSe 


144 


■ ••• 


100-00 


99-40 


99-92 



B. Selenite op Lead-oxide, or Lead-selenite. — a. Ba^ic. — By 
strongly igniting 6, or by treating it with carbonate of ammonia. — Trans- 
lucent, friable, fusible substance, having a crystalline fracture. 

b. Monobasic. — Found native, sometimes alone, sometimes mixed 
with Tile-ore (^Kupferj)echerz),^^Qiemo\is acid and alkaline selenitea pre- 
cipitate lead-oxide from its solution in hydrochloric or nitric acid ; in the 
latter case, however, the precipitate retains a small portion of nitric acid. 
The pure salt is obtained by precipitating aqueous chloride of lead with 
excess of selenite of ammonia. — White, heavy powder, which fuses almost 
as readily as horn-lead, forming a yellowish translucent liquid, which, on 
cooling, yields a white, opaque substance, having a crystalline fracture. 
At a strong red heat, it gives off selenious acid with ebullition, and leaves 
the salt a. Decomposed with difficulty by boiling sulphuric acid. Scarcely 
soluble in water, even when free selenious acid is present. (Berzelius.) — 
The native selenite has a globular structure, fibrous fracture^ and sulphur- 



140 LBAD. 

yellow colour. It decrepitates when heated, without giving off water, 
and at a red heat fuses into black drops, evolving a small quantity of 
selenium, and afterwards selenious acid, when the heat is still further 
increased. On charcoal, before the blowpipe, it fuses to a black sl^, 
evolving a strong odour of selenium, covering the charcoal with lead- 
oxide, and yielding reduced lead in ductile grains, the reduction being 
attended with ebullition. It dissolves in warm nitric acid without effer- 
rescence. (Karsten, Pogg. 46, 277-) 

Berzelins. 

PbO 112 .... 66-67 66-67 

SeO» 56 .... 33-33 33-33 

PbO,SeO>.... 168 100-00 100-00 

C. Seleniate op Lead-oxide, or Lead-seleniate. — By precipitating 
seleniate of soda with nitrate of lead-oxide (II., 240). White powder, 
insoluble in water. (Mitscherlich.) 

Lead and Iodine. 

A. Iodide op Lead. — 1. Formed by precipitating a lead-salt with 
aqueous hydriodic acid, iodide of potassium, or iodide of iron (Grajr-Lussac) 
or nitrate of lead-oxide by iodide of potassium (Boullay, Ann, Ckim, Pkys, 
84, 46), or acetate of lead-oxide by iodide of potassium. The lead- 
acetate must not be in excess, otherwise oxy-iodide of lead will be precipi- 
tated together with the pure iodide. (Ingfis, Brandes, Ann, Pharm. 10, 
266.) When acetate of lead-oxide is added in successive portions to iodide 
of potassium, the iodide of lead is first precipitated as a yellow powder, 
and afterwards in yellow laminaa resembling those of mosaic gold, and the 
liquid, which retains a small quantity of iodide of potassium, turns acid; 
acetate of lead-oxide added in excess to this liquid forms pale yellow, 
shining scales, containing oxy-iodide of lead. If a solution of 1 part of 
iodide of potassium in 10 parts of water, be mixed with a very small 
quantity of acetic acid, the addition of lead-acetate prodaces crystalline 
iodide of lead at once; but if too much acetic acid is present, the iodide 
remains dissolved, and does not separate till the acid is neutralised by 
potash or ammonia. The crystals are finer as the solutions are more 
dilute. (0. Henry, J, Pharm, 17, 267.) — To obtain iodide of lead in fine 
crystals, dissolve 1 part of iodide of potassium in 10 parts of water, then 
add a sufiScient quantity of iodine to give the liquid a slight yellowish- 
brown colour, and precipitate by gradually adding a dilute solution of 
lead-acetate. (Hoppl, Kastn, Arch, 22, 71.) The product may be purified 
by crystallization from a solution in boiling water. (Boullay, Brandes.) 
— When iodide of potassium is precipitated by acetate of lead-oxide 
mixed with acetic acid, a greenish or dark blue iodide of lead is thrown 
down, containing excess of iodine which cannot be extracted by water, 
but may be dissolved out by alchohol or by aqueous solution of potash. 
When iodide of iron is precipitated by acetate of lead-oxide, the preci- 
pitate contains a small quantity of iron, which may be almost wholly 
extracted by water acidulated with acetic acid. — 2. Iodide of lead may 
be obtained in octohedrons by electrolytic action. (Becquerel, vid, I., 
401.) 

Orange-yellow powder, or golden-yellow, flexible six-sided ^laminaa 
(Boullay, Denot); short six-sided prisms (Inglis). Specific gravity 
6-0282 (Karsten), 61 10 (P. Boullay). Acquires a reddish-yellow colour. 



LEAD AND IODINE, 141 

when heated, afterwarcU becoming brick-red and red-brownish-black* 
(O. Henry, Brandes.) Fuses when somewhat strongly heated (Gay* 
Lnssao), forming a translucent, red-brown liquid, which, on cooling, 
solidifies in a yellow mass. (Brandos.) Volatilizes at a strong red head. 
(H. Davy.) 

Brandes. Denot. O. Heniy. 

* " > 

laminar, laminar, pulvenUentm 

Pb 104 .... 45-22 .... 44-98 .... 44*10 .... 50-27 .... 5200 

1 126 .... 54-78 .... 5502 .... 5485 .... 5115 .... 4738 

Pbl .... 230 .... 10000 .... 10000 .... 98-95 .... 101-42 .... 9938 
O. Henry calculates his analyses differently; but his calculations are incorrect. 

Iodide of lead gives off iodine when heated [in contact with the airj, 
and the lemon-yellow mass, after cooling, dissolves for the most part m 
boilinff water, leaving a residue of oxy-iodide of lead. (Brandes.) When 
heated in chlorine gas, it is converted into chloride of lead. (Brandes.) — It iff 
decomposed by boiling with water and iron, or still more readily with 
zinc, yielding metallic lead, and iodide of iron or zinc, which dissolves. 
(Berthemot, J. Pharm. 13, 412.) When boiled with water and carbonate 
of soda, baryta, strontia, lime, or magnesia (most slowly with the last), it 
yields carbonate of lead-oxide, and a solution of iodide of sodium, barium, 
&c. (Berthemot.) Dissolves in aqueous sal-ammoniac even when cold 
(Brett), more abundantly in a hot solution, — and as the liquid cools, 
yellowish-white needles, probably of a double iodide, separate out. 
(BouUay.) In aqueous ammonia, or nitrate or succinate of ammonia, it 
slowly turns white without dissolving; in carbonate or sulphate of 
ammonia the change takes place more quickly. (Wittstein, Repert. 63, 
331.) — By repeated boiling with ether^ which extracts the iodine and 
thereby acquires an orange-yellow colour, it is converted into pale yellow 
oxy-iodide of lead. (A. Vogel, J.pr. Chem. 22, 148.) — Dissolves in 1235 
parts of cold, and in 194 parts of boiling water (Denot); in 187 parts of 
boiling water. (Berthemot) The solution is colourless (Denot), and if 
saturated while hot, deposits crystals of pure iodide of lead on cooling. 
(Boullay.) When this compound is dissolved in boiling water, a faint 
odour of iodine becomes apparent. (Caventon, J, Pharm. 17, 266.) The 
crystals of pure iodide of lead are completely soluble in water (Brandes); 
any oxy-iodide of lead that may be mixed with them remains undissolved. 
(Caventou.) The addition of acetic acid to the water does not increase 
the solubility of the pure iodide. (Denot, J, Pharm, 20, 1; also J.pr, 
Chem, 1, 425.) — Iodide of lead dissolves in a concentrated solution of 
iodide of potassium, sodium, barium, strontium, calcium, or magnesium, 
and is again completely precipitated on the addition of water. (Ber« 
themot.) — It appears also to be slightly soluble in alcohol. (0. Henry.) 



B. OxY-iODiDB OP Lead. — a. PbI,PbO. — 1. By precipitating iodide 
of potassium with a very large excess of lead-acetate. The precipitate 
is left for a while in contact with the liquid, and then boiled with water 
to extract the free iodide of lead. The orange-yellow colour of the 
precipitate changes to a paler yellow, and the liquid is found to contain 
free acetic acid. Also when 100 parts of iodide of lead are left for 
several days in contact with solution of lead-acetate, and agitated every 
now and then, a quantity of oxy-iodide is obtained amounting to 147 or 
148 parts. (Brandes, Arm, Pharm. 10, 269.)— I^^not {J, Pharm, 20, 1) 



142 , LEAD. 

dropa iodide of potaflsiiim into a solatioa of lead-aeetate which haa heen 
exposed to the air, and boils the precipitate with water. — Gregory 
(/. Pkarm, 18, 24), by mixing dilute eolations of iodide of potassium and 
sugar of lead, obtained, on cooling, small, dingy greenish-yellow needles, 
mixed with a few orange-yellow crystals of iodide of lead, which could be 
completely removed by boiling water. The analysis of these needles is 
given befowj Gregory regards them as diniodide of lead, Pb'I. In 
subsequent trials, however, he did not sncceed in obtaining these needles 
[probably because he did not use the lead solution in excess]. — 2. By 

firecipitating iodide of potassium with ordinary subacetate of lead-oxide 
which usually contains about 2 At. lead-oxide to 1 At. acetic acid]. 
(Brandes.) — Pale lemon-yellow precipitate, or, according to Gregory, 
greenish -yellow needles. — Fuses between 200° and 300°, giving off white 
fumes mixed with vapour of iodine, and leaves an amber-eoloured, trans- 
parent, very elastic glass, containing iodine and silica, besides oxide of 
lead. (Denot.) — When heated in chlorine gas, it is converted into ehloride 
of lead. (Brandes.) — When treated with acetic acid, it gives np lead-oxide, 
the iodide remaining undissolved. (Brandes, Denot.) — Insoluble in boiling 
water. Not altered by aqueous ioaide of potassium. (Brandes.) 





Or; 


Pbl 

PbO 




Calculation. 

230 

112 


67-25 
32-75 






Pbl, PbO 

.. 208 ... 
.. 126 ... 

o ... 




342 

Bnmdes. 
60-13 

• •••ft ••••< 


100-00 

Denot. 

(1) 
60-45 ... 

.. 36-88 ... 




2Pb. 
I .. . 
O.... 


60-82 
36-84 . 
2-34 


Gregory 

62-1 

37-9 









342 ... 10000 100-0 

h. PbI,2PbO. — By precipitating trisacetate of lead-oxide with excess 
of iodide of potassium.— c. PbI,5PbO. — By decomposing sexbasic acetate 
of lead-oxide with excess of iodide of potassium. Denot speaks, indeed, 
merely of lead-acetate {Acetate plombique), but there is no doubt that he 
alludes to the sex-basic salt. — The compounds b and c behave like a, 
when fused. (Denot.) Oxy-iodide of lead is also formed on boiling 
iodide of lead with carbonate of lead-oxide in water. (Denot.) 







6. 


Or: 






Denot. 


Pbl 


230 


... 50-66 


3Pb 


. 312 


... 68-72 


67-3 


2PbO 


224 


... 49-34 


I 


. 126 


... 27-76 


26-6 


• 






20 


16 


... «J*dA .. 


.... 0*D 


PbI,2PbO... 


454 


... 100-00 




454 


... 100-00 


97-4 



T According to Kiihn (Arch. Pharm. [2], 50, 281), the precipitate 
formed by iodide of potassium in trisacetate of lead-oxide is not PbI,2PbO, 
but Pbl,rb0 + HO. — Ammonia added in excess to a boiling-hot solution 
of iodide of lead, forms a white precipitate, which turns yellow when 
gently heated, and corresponds nearly to the formula PbI,dPbO + HO. IT 

0. Iodide of Lead and Hydrogen. — 1. Aqueous hydriodic acid, 
exposed for some time to the air in contact with lead-filings, gradually 
deposits white crystals, which dissolve when the whole is boiled, and 
assume a finer appearance on cooling.— 2. The solution of iodide of lead 



LEAD AND IODINE. 143 

in bot aqneona hydtiodio acid jields the same orysials on cooling.— « 
White oiTBtaLs having a silky lustre. The compound, when kept in 
Taouo or m dry air/ gradually gires off hydriodic acid and leaTes iodide 
of lead: the same change takes place quickly on the application of heat. 
Cold water likewise extracts the hydriodic acid with only a small 
quantity of iodide of lead. Boiling water dissolves the salt completely, 
hut the liquid, on cooling, deposits crystallized iodide of lead, and 
retains the hydriodic acid in solution. (Guyot, J. Chim. Mid. 12, 247.) 

When fused iodide of lead is decomposed in the voltaic circuit, iodine 
is evolved at the positive pole, hat a periodide of lead seems likewise to 
he formed, which evolves iodine when heated somewhat strongly. (Fara- 
day, Exp, Bes. inM.^, 236; also Pogg. 83, 485.) 

D. Basic Periodic of Lead-oxide i — a. Blue Salt. — First ohserved hy 
Denot.— 1. A solution of 1 At. iodine in 1 At. aqueous soda (carhonate 
of soda is not so good) forms with nitrate or acetate of lead-oxide, a 
transient violet-red precipitate, which decomposes spontaneously under 
water, yielding iodine and a heautiful blue powder. — 2. But if only 
4 At. or ^ At. iodine is dissolved in 1 At. soda, the hlue precipitate forms 
immediately, and the solution retains but a trace of iodine. — 3. Also, 
when hydrated lead-oxide is triturated with iodine precipitated by water 
from an alcoholic solution, a violet-red mass is obtained, which, after a 
while, gives off iodine and turns blue. — The blue powder gives off no 
iodine in vacuo; it likewise remains unaltered in water and in solutions 
of lead- acetate and of sugar, but the weakest acids, even the carbonic 
acid of the air, separate iodine from it and form a lead-salt. When 
heated alone, it does not evolve iodine, but turns greenish-yellow, 
perhaps from formation of iodide of lead and basic iodate of lead-oxide, 
(Durand, N. J. Pharm, 2, 311.) 

&. Violet Salt, — Litharge exerts little or no action on a mixture of 
iodine and water, even with the aid of heat; but pure hydrate of lead- 
oxide mixed with iodine and cold water forms, in a few seconds, a pale 
violet-coloured compound, which, after the excess of iodine has been 
expelled by boiling, must be washed and then dried out of contact of air. 
The hydrated lead-oxide may likewise be treated with an alcoholic 
solution of iodine, and the excess of iodine removed by washing with 
alcohol. — The pale violet compound contains 83*82 per cent. (6 At.) of 
lead-oxide and ]6'23 per cent. (1 At.) of iodine. — At a strong red heat, 
it gives off oxygen gas and leaves iodide of lead [mixed with oxide]. 
It absorbs carbonic acid from the air without evolving iodine. The 
stronger acids separate iodine from it, Caustic potash dissolves it 
gradually. It is but slowly decomposed by boiling with water, and does 
not yield iodine to alcohol. — To obtain the blue compound a, hydrated 
lead-oxide must be mixed with iodine and water, and a few drops of 
nitrate or acetate of lead-oxide added. (Jammes, N, «/, Pkarm, 3, 356.) 
— [Can the compound 6 be composed of PbI + llPbO,IO, and the com- 
pound a distinguished from it by containing less oxide of lead?] 

E. loDATB OF Lbad-oxide, or Lead-iodate. — Iodic acid and iodate 
of potash or soda, give an immediate precipitate with nitrate of lead-oxide. 
(Pleisohl, Schw, 45, 18.) — White powder, anhydrous after drying. When 
gently ignited in a retort, it gives off a large quantity of iodine and 
oxygen gas, and leaves 52 '25 per cent, of a yellowish-brown residue, 
containing iodide and oxide of lead, the former of which remains nndis- 



144 LEAD. 

solved when the residae is digested in aoetio acid. (Rammelsbergy ^ogg* 
44, b^%.^ With concentrated hydrochloric acid, it yields chlorine gas, 
water, dissolved terchloride of iodine, and crystalline chloride of lead. 
(Filhol.) 

PbO, I0» + 6HC1 = Pba + ICP + 6H0 + 2C1. 

It dissolves very sparingly in water, and with some difficulty in nitric 
acid. (Rammelsberg.) 

F. BiBASio Pbriodate of Lead-oxide. — Formed b^ precipitating 
nitrate of lead-oxide with bibasic periodate of soda dissolved in the 
smallest possible quantity of warm, dilute nitric acid. If too much 
nitric acid be added to the solution, the filtrate will contain periodic 
acid, and will then yield an additional quantity of lead-salt on digestion 
with carbonate of lead- oxide. Monobasic periodate of soda likewise 
throws down bibasic periodate of lead-oxide from a solution of the 
nitrate, the supernatant liquid becoming charged with free acid. — White 
powder, which becomes yellowish when dried or heated, or by loss of 
water. Decomposed by dilute sulphuric acid. Dissolves readily in dilute 
nitric acid, but not in aqueous periodic acid, or in pure water. (Benckiser, 
Ann. Fharm. 17, 254.) 

Lead and Bromine. 

A. Bromide of Lead. — 1. By treating lead-oxide with aqueous 
hydrobromic acid. Lead -oxide treated with bromine- water is immediately 
converted into peroxide of lead. — 2. By precipitating a lead-salt witn 
aqueous bromide of potassium. (Balard.) — When prepared according to 
(2), it is a white crystalline powder. (Balard.) From a solution in hot 
water, it separates in white shining needles. (Lowig.) After rapid 
drying it has a density of 6'6d02. (Karsten.) At a strong heat, it fuses 
inlo a red liquid (Balard); and if the fusion takes place in a vessel which 
excludes the air, the salt solidifies on cooling, in a white, horny mass. 
(Lowig.) When fused in contact with the air, it emits a small quantity 
of white fumes, and on cooling solidifies in a yellow mass consisting of 
oxybromide of lead. (Balard.) — Nitric acid added to pulverized bromide 
of lead liberates bromine, sulphuric acid causes the evolution of brominic 
and hydrobromic acid; the fused bromide, on the contrary, is decomposed 
only by boiling oil of vitriol. (Balard.) Bromide of load dissolves 
sparingly in cold water, more readily in water containing hydrochloric, 
nitric, or acetic acid. (Lowig.) It dissolves slowly in cold aqueous 
hydrochlorate or nitrate of ammonia, quickly in the same solutions when 
warm. (Wittstein.) 

Lowig. 

Pb 104-0 ... 5702 59-2 

Br 78-4 ... 42-98 40-8 

PbBr 182-4 Z. 10000 ZZ lOO'O 

B. Oxybromide of Lead. — 1. Formed by igniting bromide of lead 
in the air, till it ceases to emit white fui^es. (Balard.) — 2. By heating 
bromo-carhonate of lead (p. 145) till all the carbonic acid is expelled. 
(Lowig.) — By placing bromide of lead for some days in contact with a 
solution of lead- acetate, and agitating from time to time. The filtrate 
contains free acetic acid. (Brandos, Ann, Fharm, 10, 275.) — Prepared 
by (1) or (2), it has a fine-yellow colour; by (3), yellowish white, but 



CIILOWDB OP LEAD. 145 

after complete dehydration at 140^, yellowish. When heated it becomes 
lemon-yellow, then reddish-yellow, then brown-red, and after cooling, 
resnmes its original yellowish- white colonr. When heated to fusion, it 
emits dense white fumes, and, on cooling, solidifies in a yellowish-white, 
translucent, pearly mass. When decomposed at a high temperature by 
chlorine gas, it yields 94*921 per cent, of chloride of lead, and is there- 
fore = PbBr,PbO. (Brandes.) 

C. Bromate of Lbad-oxidb, or Lead-bromate. — 1. Bromic acid 
and bromate of potash throw down a white powder from lead-salts, but 
only from concentrated solutions. (Balard.) — 2. The salt may be formed 
by dissolving carbonate of lead-oxide in warm bromic acid, and leaving 
the solution to crystallize. (Rammelsberg.) —Small, shining, permanent 
crystals, isomorphous with those of the strontia-salt. — They do not lose 
their water in vacuo over oil of vitriol. At 1 80®, they begin to decom- 
pose, with copious evolution of gas, forming brown oxide of lead, which, 
at higher temperatures, is reduced to the red and then to the yellow 
oxide, the latter remaining in combination with bromide of lead. Soluble 
in 75 parts of cold water. (Rammelsberg, Pogg. 52, 96.) 

Crystallized. Rammelsberg. 

PbO 1120 .... 46-78 4639 

BrO* 118-4 .... 49-46 

HO 9-0 .... 3-76 

PbO,BrO* + Aq 2394 .... 10000 

D. Bromocarbonate ov Lead. — Equivalent quantities of bromide 
of lead and carbonate of lead-oxide, boiled with water, form an insoluble 
compound, which fuses readily when heated, and afterwards gives off its 
carbonic acid. (Lowig.) 

Lead and Chlorine. 

A. Chloride op Lead. — Plunilmm-corneum, Horn-lead. — Found 
native as CotunniU. — 1. Lead absorbs chlorine gas very slowly, and 
without visible combustion. — 2. Hydrochloric acid added to leaa-oxide 
or its salts forms chloride of lead; and dissolved metallic chlorides added 
to solutions of lead-salts throw down the same compound in the form of a 
crystalline powder. — 3. With metallic lead, hydrochloric acid forms 
chloride of lead, but very slowly, and only when assisted by the action 
of the air. The same acid boiled with metallic lead^ converts it into 
chloride, with evolution of hydrogen gas. — When prepared by (2), it 
forms a white crystalline powder, known by the name of Magisterium 
Plumbi; when crystallized from a hot solution in water or aoueous acids, 
it forms white, silky, six>sided needles and laminsB. Fuses below a red 
heat, and on cooling solidifies in a white, translucent, horny mass. 
According to J. Davy, it does not volatilize even at a very strong red 
heat, provided the air be excluded. Specific gravity of the precipitated 
chloride 5*8022; of that which has oeen fused out of contact of air, 

5-6824. (Karsten.) 

J. Davy. Dobereiner. 

Pb 104-0 .... 74-6 74-22 75*76 

CI r...., 35*4 .... 25-4 2578 24'24 

FbCl .... 139-4 .... 100-0 100-00 lOO'OO 

▼OL. V. !• 



146 LEAP, 



Or: 

PbO 1120 .... 80-34 

Cl-0 .... 27-4 .... 19-66 



Benelrai. 


KirwMi. 


80-26 


81-77 


19-74 


18-23 



139-4 .... 100-00 100-00 lOO'OO 

When ignited in contact with the air, it partly volatilizes, together 
with excess of chlorine, leaving a residue of oxychloride of lead. (Dobe- 
reiner, Schto, 17, 255.) When fosed with sulphur, it is partially con- 
verted into sulphide of lead. (A. Vogel.) It is completely decomposed 
by carbonic oxide, at a red heat, yielding phosgene gas and metallic lead. 
(Gfbbel, J. pr. Pharm. 6, 388.) — With phosphuretted hydrogen gas, at a 
gentle heat, it yields hydrochloric acid, phosphorus, and metalUc lead« 
(H. Rose, Poffff, 24, 334.) — With aqueous hypochlorous acid, it forms 
peroxide of lead and chlorine gas. (Balard.) — Aqueous alkalis convert 
it into Quadrobasic hydrochlorate of lead-oxide. — Chloride of lead dia- 
solves slowly in 135 parts of water at 12*5° (Bischof), and in a smaller 
quantity of ooiling water. Of cold water containing hydrochlorio aoid, 
it requires 1636 parts to dissolve it — twelve times as much, therefore, as 
of pure water (Bischof); hence a precipitate is formed in the aqneoui 
solution on the addition of hydrochloric acid. (H. Rose.) On the other 
hand, concentrated hydrochloric acid dissolves chloride of lead abundantly, 
and is precipitated by water. (6m.) A solution of chloride of calcium, 
even if dilute, likewise precipitates the aqueous solution of this compound, 
leaving a solution containing 1 part of chloride of lead in 534 parts of 
water. (Bischof, Schw, 64, 76.) The solution in strong hydrochloric acid 
is not precipitated by sulphuretted hydrogen; but immediately on the 
addition of water. ( Wackenroder.) Chloride of lead dissolves somewhat 
abundantly in aqueous alkaline hyposulphites (Herschel), also in aqueous 
acetate of soda. If, therefore, 190 parts of leacUacetate dissolved in 
water, are mixed with 58*7 parts of common salt, from 43 to 48 parts of 
chloride of lead are precipitated; the filtrate, on further evaporation, gives 
off acetic acid, and deposits the greater part of the chloride [or oxy- 
chloride ?] of lead, so that at length only 4' 4 parts remain in solution. 
A small quantity of common salt added to a solution of lead-acetate forms 
a precipitate which disappears on agitation; a small quantity of lead- 
acetate solution added to a solution of common salt forms a permanent 
precipitate; if, however, acetate of soda is mixed with the solution of common 
salt, no precipitate is formed. (Anthon, ReperL 76, 229.) — Chloride of lead 
dissolves very sparingly in alcohol of 76 per cent., the solubility not being 
increased by heat. In spirit of 94 per cent, it is insoluble. (Bischof.) 



B. Oxychloride op Lead. — a. 3PbCl, PbO.— 4 parts of chloride of 
lead ignited with 1 part of litharge, yield a fused, laminar, pearl-grey 
mixture, which, when triturated with water, swells up to a bulky mass. 
(Vauquelin.) 

6. PbCl, PbO. — Formed by iifniting chloride of lead in the air till it 
no longer gives off fumes, or by uising together chloride of lead and car- 
bonate of lea<l-oxide, whereby the carbonic acid is set free. The mixture 
while fased is of a deep-yellow colour, and as it cools, becomos first lemo^- 
yellow, then of a pearl colour and crystalline. (Dobereiqer.) If pulve- 
rized crystalline chloride of lead be left for some days in contact with a 
concentrated solution of le^-acetate, it takes up protoxide of lead with 
evolution of acetic acid, and forms a white powaer, which, after washing 
and drying at a gentle heat, contains from 2 to 2*5 per cent, of water. 
At a stronger heat the water escapes, the compound assuming first a 



Berzelius. 


Rhodius. 


34-63 


39-06 


Oo'o£ itaa< 


60-10 


7-55 




1-46 




0-54 





OXYCHLOiaQB OF LEAD. 147 

yellowlBh-white and then a light yellow tint; and the residue ultimately 
rases to a deep yellow liquid, which gives off white fumes, and on coolingj 
solidifies to a nearly white mass containing 55*36 per cent, of chloridi^ 
of lead and 44*45 per cent, of oxide. (Brandes, Ann. Fharm. 10, 274.) 

c. PbCl,2PbO. — Mendip Leadrore or Mendipite, — ^Right rhombic prism. 
wri/rrT?® 33'. Cleayage parallel to p and u. Sp. gr. = 7*077. Harder 
than gypsum. Yellowish-white, with an adamantine lustre; translucent. 
Decrepitates when heated, and appears yellower after cooling. Fuses 
very readily. Yields lead before the blowpipe upon charcoal, with eyolu- 
tion of acid vapours. The carbonate of lead-oxide, the quantity of which 
is variable, and the silica, are to be regarded as accidental admixtures. 
(Berzelius, Pogg. 1, 272.) — IT This mineral is likewise found, and in a 
state of greater purity, at Brilow near Stadtbergen : it there occurs in 
connexion with calcspar and calamine. Structure crystalline. Cleavage 
distinct. Very slightly brittle. White, translucent, with a mother-of- 
pearl lustre on the cleavage-surfaces. Sp. gr. = 7*0. (Rhodius, Ann, 
Pharm. 62, 373.) T 

Mendipite, 

Pba 139-4 .... 38-36 

2PbO 224-0 .... 61-64 

PbO,CO» .... .... 

Si02 .... 

HO .... 

PbCl,2PbO.... 363-4 .... 100*00 ZZ 10000 IZ! 99*16 

d. PbCl, 3PbO. — ». Anhydrous. — 1. By fusing 1 At. chloride of lead 
with 3 At. of the protoxide. — 2. By fusing the hydrated compound.-^ 
Greenish-yellow, with a laminar texture; yields a pale yellow powder. 
(Dbbereiner.) — ^, Uydrated, PbCl, 3PbO-|-HO, or Quadrobasic Hydro- 
chlorate of Lead-oxide, 4PbO, HCl. — 1. By decomposijig chloride of 
lead with an aqueous alkali. Berzelius precipitates an aqueous solu- 
tion of chloride of lead with ammonia. — 2. By precipitating subacetate 
of lead-oxide with a solution of common salt. (Berzelius.) — 3. By 
decomposing a solution of common salt with lead-oxide. Scheele has 
shown that soda may be separated from salt by this process. Accord- 
ing to Vauquelin (ScL J. 4, 51), 1 part of common salt requires 7 parts 
(rather more than 4 At.) of finely pounded litharge. The mixture 
worked up with water to a thick pulp, turns white and thickens, the 
lead-oxide swelling up; hence it is necessary to add repeatedly fresh 
quantities of water and work the mixture up again. On diluting with 
water after four days, and filtering, the filtrate is found to contain 
nothing but caustic soda with a small quantity of chloride of lead dissolved 
in it; but no common salt. — According to later experiments of Anthon 
{Eepert, 77, 105), the chloride of sodium is but half decomposed, even 
when ten times its weight of lead-oxide is used, and the mixture is left to 
stand for 12 days and &equently agitated. White flocculent mass, which 
when heated gives off 7 per cent, of water, and is converted into PbCl, 
3PbO. Acids dissolve out the oxide of lead, and leave the chloride. The 
compound is almost wholly insoluble in water, slightly soluble in caustic 
soda. (Vauquelin.) 

e. PbCl, 5PbO. — By fusing 1 atom of chloride of lead with 5 atoms of 
the protoxide. — Orange-yellow substance, yielding a powder of a deep 
yellow colour. (Dobereiner.) 

/. Cassel-yelloto. — Commonly prepared by fusing a mixture of 1 part 
of i^-ammoniac with about 10 parts of massicot, minium^ or white lead, 

l2 



148 LfiAD. 

Part of the sal-ftmmoniao sublimes nndeeomposed, so that the compoutid 
contains about 7 At. lead-oxide to 1 At. chloride. Part of the lead is 
at the same time reduced by the ammonia. The compound has a fine 
yellow colour, and crystallises in radiated lamin®. 

C. Chlorite of Lead-oxide, or Lbad-chloritb. — By precipitating 
chlorite of baryta which contains a large quantity of free chlorous acid 
and is in excess, with mononitrate of lead-oxide, and washing the preci- 
pitate with water. An excess of lead-nitrate would partially dissolve the 
precipitate. — Sulphur-yellow, crystalline scales. Decomposes at 126^ 
with a kind of explosion. Sets fire to flowers of. sulphur which are tritu- 
rated with it by means of a glass rod. Blackens at first in hydrosulphuric 
acid gas, then immediately turns white by conyersion into sulphate of 
lead-oxide. With a mixture of equal parts of water and oil of ritriol, it 
evolyes pure chlorous acid gas, especially between 40° and 50°, and yields 
88*75 per cent, of lead-sulphate. (Millon, N, Ann, Ckim. Fhys, 7, 327.) 

dywiatHzed. MiUoD. 

Pb 112-0 .... 65-34 65-39 

C10» 59-4 .... 34-66 

PbO,C10» 171-4 .... 100-00 

D. Chlorate of Lead-oxide. — By dissolyins; lead-oxide in aqueous 
chloric acid, the salt is obtained in white shining laminse, the solution of 
which is colourless, has a rough, sweet taste, and does not redden litmus. 
(Vauquelin, Jnn. Ohim, 95, 127.) — IT By cooling a hot solution of this salt, 
rhomboidal prisms are obtained, which become dull and opaque by 
exposure to the air. They are composed of PbO, ClO^H-HO. They do 
not deliquesce, but are easily soluble in water and in alcohol. When 
heated, they leaye an oxychloride of lead, of yellow colour and haying 
the constant composition: PbO, 2PbCL (Wachter, Ann, Fharm. 52, 
233.) IT 

E. Perchlorate of Lead-oxide.— The solution of lead-oxide in 
warm aqueous perchloric acid yields small prisms haying a sweet but 
highly astringent taste, soluble in about their own weight of water, and 
not deliquescent. (SeruUas, Ann, Ckim, Fhys. 46, 306.) 

F. Chlorocarbonatb of Lead. — Found natiye as Bbm-lead, or 
Corneous lead-ore. — Square prisms. Fig. 28, 32, 33, 39, and other forms; 
p : ^=123** 6' (Brooke). Specific gravity =6'06. Hanier than gypsum; 
colourless and translucent. — When 1 At. carbonate of lead-oxide is boiled 
with 1 At. (or more) chloride of lead and with water, the chloride is 
rendered insoluble by combining with the carbonate. — White, heayy 
powder. — Both the natural and the artificial compound fuse yery easily, 
and at a higher temperature are conyerted, with ebullition and loss of 
7*75 per cent, of carbonic acid, into the oxychloride of lead b. (Dobe- 
reiner, Schw, 17, 251; Berzelius, JSyst, d. Mineral. 241.) 

Klaproth'fl analygis 
Hom-lead. (recalculated.) 

Pba .^ 139-4 .... 50-99 63-83 

PbO 112-0 .... 40-96 42-90 

CO* 22-0 .... 8-05 6-100 



PbCl,PbO,CO>... 273-4 .... 10000 102-73 



PYROMORPHITE. 



149 



G. Chlorophosphitb of Lead. — Lead-salts added to terchloride of 
phosphorus dissolved Id water and neatralized with an alkali, throw 
down a compound of phosphite of lead-oxide and chloride of lead, from 
which boiling water extracts the latter. (Berzelius.) 

H. Chlorophosphatb of Lead.— PbCl-f-3(3PbO,<5PO«.)— To this 
head belongs Pyromorphite {Green Lead-ore or Broum Lead-ore). 
Crystalline system^ the hexagonal. Fig, 131, 135, 137, 138, and other 
forms. r:r*=81°46'; r:<r=130'' 53'. Cleavage imperfect, parallel to 
r and a (if any). Sp. gr. =6*9. ...7*0. Hardness equal to that of apatite. 
Variously coloured; with a fatty lustre; translucent. Fuses easily, and, on 
cooling, solidifies with vivid incandescence to an angular crystalline mass. 
Fused with carbonate of soda upon charcoal, it yields metallic lead. Its 
solution in nitric acid gives a turbidity with nitrate of uilver-oxide. In 
some of these ores, the chloride of lead is partly replaced by fluoride of 
calcium, and the triphosphate of lead-oxide by triphosphate of lime or 
trisarseniate of lead-oxide. The calcareous ores may (with Fuchs) be 
regarded as mixtures of Apatite and P3rromorphite. The arsenical 
ores fuse upon charcoal before the blowpipe and yield metallio lead. 
(H. Rose.) 

Wt^hler. 



Pyromorphite. 

lOPbO 1120-0 .... 82-26 

Cl-0 27-4 .... 2-01 

3cPO» 214-2 .... 15-73 

AaO* 

PeSO" 

CaO 



a. 
82-29 

1-98 
15-73 

trace 



80-55 
1-99 

1413 
2-30 
trace 



e. 
82*46 

1-95 
15-50 
trace 
trace 



d, 

75-59 

1-89 

1-32 

21*20 

trace 



1361-6 



Or: 

PbCl 139-4 

CaF 

3(3Pb67cP6*) 1222-2 

3C»0,cPO*.... 

Fe«03 



100-00 



100-00 



98-97 



.... 99-91 
Kersted. 



100-00 



10-24 
89-76 



e. 
10-09 

89-91 

trace 



10-08 
013 

89-11 
0-68 



9- 
9 92 

0-14 

89-17 

0-77 



1.361*6 



100-00 



100-00 



100*00 



100-00 



Kersten. 



PbCl 

CaF 

3(3PbO,cPO*) 

3CaO,cPO* 

Fc*05 



A. 

9-66 

0-22 

89-27 

0-85 



1. 

10*64 
0*25 

81-65 
7-46 

trace 



k. 
10-84 

1*09 
77*02 
11*05 



100*00 



100-00 



100-00 



a. is Green Lead-ore from Tschoppau. — 6. White variety from Tschop- 
pau. — c. Ore from Leadhills, in aurora-red hexagonal prisms. — d. Ore 
from Johann Georgenstadt, in wax-yellow, acuminated prisms. (Wohler.) 
— e* Crystallized Brown Lead-ore from PouUaouen.— /. The same from 
England. — g. The same from Bleistadt, of specific gravity 7*009. — A. The 
same from Mies, of specific gravity 6-983. — i, Botrymous Brown Lead- 
ore from Mies, of specific gravity 6-444. — k, Botrymous Brown Lead- 
pre from the Sonneuwirbel mine near Freiberg, of specific gravity 6*0i>2. 



1^0 LEAD. 

fBreitbaiipt's Potyipheriie.) (Karsten, Sekyf. 63, 1.) — In Breitbanpt's 
ffedyphane, from Longbansli jttan, of specific ^praVity 5*496, Kenten fonnd 
PbCl 10-29,— 8CaO,PO' 15-51,— 3GaO,A80» 12-98,— 8PbO,A80» 6010 
(loss 1-12). — In an orange-yellow pbospbate of lead from Wanlockhead 
Vernon {FhU. Mag. Ann, 1, 321; also Schw. 52, 187) found: PbCl 1007, 
3PbO,cPO*87e6,— PbO,CrO> 1-20,— lime, silica, ferric oxide, water and 
combustible matter, 0*40. 

^ Tbe same compound, containing, bowever, an atom of water, is 
formed artificially on pouring a boiling solution of cbloride of lead into a 
solution, likewise boiling, of pbospbate of roda, tbe latter being in 
excess. Tbe precipitate is insoluble in water, but dissolves in nitric 
acid, wbicb converts it into tbe pbospbo-nitrate of lead-oxide discovered by 
Berzelius (p. 1 58). Tbe composition of the precipitate is: 3{3PbO,PO*) + 
PbCl-f HO. (Heintz, Pogg. 73, 122.)— When, on tbe contrary, a boiling 
solution of pbospbate of soda is poured into an excess of cbloride of lead, 
a precipitate is formed, wbicb, according to Heintz, is composed of 
2(3PbO,PO«)-fPbCl), but, according to Gerhardt {N. Ann. Ckim. PhyB. 
22, 505), of 2PbO,HO,PO« + PbCl. Tbe same compound may be formed 
wben a pbospbate is precipitated by a lead-solution in presence of a 
soluble chloride. IT 

I. Chlorosulphide of Lead. — Wben a leadnsalt, e,g. aqueous cbloride 
of lead, is precipitated by a mixture of sulphuretted hydrogen water 
and hydrochloric acid, there is produced, first a yellowish-red and then a 
red precipitate containing about 56 per cent. (3 At.) of sulphide and 44 
per cent. (2 At.) of cbloride of lead. An excess of sulphuretted hydro- 
gen water turns it black and converts it into pure sulphide of lead ; the 
same change is produced by boiling with water, which extracts the chlo- 
ride; the compound is also blackened by potash, which extracts the 
chlorine. (HUnefeld, J,pr, Chem, 7, 27.)— When sulphuretted hydrogen 
is passed through a solution of ^ pt. lead-acetate in 100 parts of 
water mixed with 10 parts of hydrochloric acid of specific gravity 
1*168, a beautiful carmine-coloured precipitate of chlorosulphide of lead 
is produced. If the solution contains 1 part of lead-acetate, 112 parts 
of water, and 14 of strong hydrochloric acid, sulphuretted hydrogen pro- 
duces a yellow precipitate, which gives op ^chloride of lead to boiling 
water, while black protosulphide of lead remains behind. — If, instead of 

14 parts of strong hydrochloric acid, we use 14 parts of a mixture of 
2 parts of strong hydrochloric and 1 pt. nitric acid, prepared two 
days before and containing hyponitrio acid, the sulphuretted hydrogen 
produces, after a while, first a yellowish-red and then a cinnabar- 
red, granular precipitate. (If the stream of sulphuretted hydrogen 
were continued for a longer time, the precipitate would become first 
carmine-coloured, then brown, and lastly black.) Tbe granular pre- 
cipitate, wben boiled with water, gives up a considerable quantity of 
chloride of lead, and is converted into a brown-red, flocculent powder, 
which then undergoes no further change, but when heated alone in a 

flass tube, gives off sulphur and bydrosulpburic acid, and fuses to a 
rown mass. According to this reaction, the byponitic acid must have 
precipitated sulphur from the bydrosulpburic acid, and the red precipitate 

15 a oomponnd of cbloride with polysulpbide of lead. (Reinsch, Eepert. 
5Qy 183; J.pr. Chem. 13, 130.) 

K. Chlorosijlphate of Lead. — 1 At. cbloride of lead fuses readily 
with 1, 2, or 4 At. sulphate of lead-oxide, forming a thin liquid. Witli 



LEAD AND FLUORINE. 151 

1 At. Iead-6iilphat6^ a white, orystalline, slightly hlistered enamel is 
ohtained ; with 2 or 4 At. the enamel is slightly erystalline. (Berthier, 
Ann. Ohm, Phy9. 43, 296.) 

L. Chloriodide of Lead. — Cold hydrochloric acid has no sensihle 
action on iodide of lead; the same acid, when boiling, dissolves the 
iodide, forming a pale reddish-^vellow solution, and on cooling yields 
pale yellow four-sided needles, irom which water gradually extracts the 
chloride of lead. (Labour^, If. J. Pharm. 4, 328.) 

LSAD AND FtVORINE. 

A. Fluoridb or Lead.*— *Lead is not attacked by hydrofluoric acid 
ai any temperature below the boiling point of that acid. (Gay-Lussao &l 
Th6nard.) — The fluoride is formed by precipitating the sUbacetate or 
normal acetate of lead-oxide with hydrofluoric acid (Scheele, Gay-Lussac 
& Th^nard), or by treating carbonate of lead-oxide with hydrofluoric 
acid (Berselius)i or with an alkaline hydrofluate. (Scheele.) — \Vhite, non-^ 
crystalline powder (Scheele), which nises readily and then solidifies in a 
yellow mass. (Berzelius.) — Not decomposed by heating in closed vessels, 
but erolyes hydrofluoric acid when heated in contact with air or vapour 
of water. (Berzelius.) — When heated with sulphur in a glass retort, it 
yields sulphide of lead, sulphurous acid gas, and gaseous fluoride of 
silicinm. Phosphorus and iodine scarcely act upon it. (Unverdarben, 
N. Tr, 9, 1, 33.) — Oil of vitriol separates hydrofluoric acid from it, even 
at ordinary temperatures. (Gay-Lussac Sc Th6nard.) Aqueous ammonia 
withdraws from it a quantity of acid just sufllcient to convert it into the 
following compound. Fluoride of lead is very sparingly soluble in water and 
not ihore abundantly in aoueous hydrofluoric acid (Berzelius, Poc/g, 1, 31); 
it dissolves more abundantly in hydrochloric and In nitric acid (Gay-Lussao 
& Th^nard), and is decomposed on the evaporation of the dissolving acid. 
(Berzelius.) 

B. OxTFLuoRiDS OF LsAD. — 1. Formed by decomposing fluoride of 
lead with aqueous ammonia.-^2. By fbsing the fluoride of an alkali-metal 
with lead-K>xide, and washing the pulverized mass with water; the oxy- 
fluorid^ is then left undissolved. — Has an astringent taste* Dissolves in 
pure water after removal of the saline liquid. The solution, when ex- 
posed to the air, deposits a crust consisting of carbonate of lead-oxide 
and flaoride of lead. (Berzelins.) 

C. Boroflvoride op Lead. — ^PbF,BF'. — Formed by adding carbo- 
nate of lead-oxide in small portions to tetra-hydrofluate of boracic acid^ 
till a precipitate is formed. The solution, evaporated to a i^rup and 
then cooled, deposits long needles; but by slow evaporation, tour-sided 
prisms or tables are obtained. Taste, sweet and astringent, afterwards 
somewhat sour. By continued boiling with water or alcohol, it is resolved 
into an cund salt which dissolves, and a basic salt which remains behind 
and forms a white powder. Another easily fusible basic compound is 
obtained by heating the borofluoride of lead with lead-oxide. (Berzelius.) 

D. Chlorofluoride of Lead. — PbCl,PbF. — 1. By precipitating 
aqueous fluoride of sodium with a boiling aqueous solution of chloride of 
lead. — 2. By precipitating an aqueous solution of 2 parts of fluoride of 
sodium and 3 parts of common salt with sugar-oMet^l. — White powder 



/ 



152 LEkD. 

which fuses when heated, withont giving off water or acid. Slightly 
soluble in water, and without alteration of the proportion of the consti- 
tuents in the residue. Easily soluble in nitric acid. (Berzelius.) 

Lead and Nitbooen. 

A. Nitrite of Lead-oxide, or Lead-nitrite.— a. Qtiadrobanc.^ 
Formed bj boiling 1 part of mononitrate of lead-oxide and l-l- parts or 
more of metallic lead in along-necked flask for 12 hours, then filtering 
and leaving the salt to crystallize by cooling. (Berzelius, GM, 40, 194 
and 200; 46, 156; Cherreul, Ann, Ghim. 83, 72; abstr. Gilb. 46, 176.) 
As the ebullition goes on, the solution first turns yellow, in consequence 
of the formation of the yellow salt B, 5, but afterwards becomes colourless 
and yields the required salt. (Chevreul.) If the boiling be not continued 
long enough to convert all the nitrate into this compound, brick-red 
needles are obtained contaminated with the salt B, a. (Chevreul, Peligot) 
-^According to Berzelius and Chevreul, the formation of the salt tS^es 
place even when the air is completely excluded, and is attended with 
some evolution of nitric oxide. The reaction is probably, therefore^ as 
follows : 

5PbO,NO» + llPb = 4(iPbO,NO») + NO». 

According to this view, 1 1 . 1 04 pts. (1 1 At.) lead re-act upon 5 . 1 66 pts. (5 At.) 
nitrate of lead-oxide =100 : 138 parts. Accordiug to Chevreul, 100 parts 
of lead-nitrate take up, after long boiling, 1 35 parts of lead, and, accord- 
ing to Berzelius, 127 parts, which is in accordance with the preceding for- 
mula. 830 parts of the neutral salt should, according to the formula, yield 
1980 parts of quadrobasic nitrate; Chevreul obtained about 1797 parts. 

Pale, fiesh-coloured, silky needles united in stellate masses (Chevreul); 
pale rose-coloured needles, or — if the solution be rapidly cooled — a 
white powder (Peligot); sometimes also of a light greenish-brown 
colour. (Bromeis.) This salt has a strong alkaline reaction. In the 
dry state it is permanent in the air. — Does not five up its water 
till heated above 100^. Loses a small portion of its acid at 100% 
and the whole at a red heat (Chevreul), the decomposition taking 
place without fusion. (Berzelius.) If part of the oxide be precipitated 
from the solution by sulphuric or carbonic acid, the liquid turns yellow; 
from 100 parts of the dissolved salt, carbonic acid gas precipitates 34*8 
parts of lead-oxide. (Chevreul.^ On dissolving the salt in cold nitric 
acid or in strong acetic acid, the acid being added gradually so that no 
heating may take place, a yellow liquid is obtained without any evolution 
of gas. The acetic acid solution of 1 00 parts of the salt, shaken up with 
peroxide of lead, takes up 49*5 parts, the nitrite of lead-oxide being 
converted into nitrate. (Peligot.) The salt dissolves in 143 parts of 
water at 25°, in 33 parts of boiling water (Chevreul); in 1250 parts of 
cold, and 3'45 of boiling water. (Peligot.) 

Berzeliua. Peligot. Cherreul. 

4PbO 448 .... 90-50 .... 9038 .... 90*52 .... 901 

NO^ 38 .... 7-68 .... 7-74 .... 9-31 .... 9'9 

HO 9 .... 1-82 .... 1'88 .... 1-93 

4PbO,NO» + Aq. 495 .... lOO'OO .... 10000 .... 101-76 .... 100*0 

Peligot found in the salt 3*43 per cent, of nitrogen, which gives 9*31 
nitrous acid (14:38=3*43 : 9*3]). 



HTPONITRATE OP LBAD-OXIDE. 153 

If h. Terhado 9 Fonned, according to Bromeis (Ann. Fliarm. 72, 50), 
by boiling tbe oraDge-red salt, B, a, for several hours in contact with 
metallic lead. Crystallizes in needles arranged in small concentric groups, 
sometimes of a brick-red colour, sometimes green and highly lustrous, 
sometimes exhibiting various shades between these two colours. The 
amount of lead in this salt was found to vary from 89*57 to 89*34 per 
cent., that of nitrogen from 3*92 to 3*56, and that of water from 0*93 to 
0*35. Bromeis regards it as an anhydrous trinitrite. Gerhardt is of 
opinion that the variable quantities of water found by Bromeis show that 
the substance which he examined was not a pure salt. 

e. Btbatic. — Formed by boiling the bibasio hyponitrate, B, b, for a 

short time with metallic lead. As the liquid cools, the salt deposits 

itself upon the hyponitrate in rather long golden-yellow needles, having 

the form of rectangular prisms terminated with rhombic pyramids, at the 

extremities of which re-entering angles occur, in consequence of the 

formation of macle-crystals. (Bromeis.) IT 

Bromoti* 

2PbO 224 .... 82*65 82*45 — 82*47 

NO» 38 .... 14*02 12-92 — 13*71 

HO 9 .... 3*33 3*87 — 3*53 

2PbO,NO»+Aq. 271 .... 100*00 IZl 99*24 "^ 99*71 

d. Ifanohasic, — Formed by passing carbonic acid gas throneh a 
solntion of a in hot water — ^whereby three^fourths of the lead-oxide is 
precipitated — and leaving the yellow filtrate to evaporate spontaneously 
(Chevreul), or in vacuo. (Peligot.) If the liquid be heated, nitrous acid 
is ^iven off. (Chevreul.) Long yellow prisms (Peligot); yellow laminse, 
(Chevreul). Very easily decomposed; very soluble in water. (Peligot, 
Ann, Chim. Fhys, 77, 87; also Ann, Fhai-m, 39, 338.) 



B. Hyponitrate of Lbad-oxide, or Lead-hyponitrate. — a. 7 At, 
b(ue to 2 At, aind, or Qttadrobasie f — 1. By boiling the solution of B, b 
with lead-oxide. — 2. By boiling 166 parts (1 At.) of lead-nitrate with 
156 parts (Ij- At.) lead and a very lar^e quantity of water, and leaving 
the yellow filtrate to crystallize by coolmg. In this process, nitric oxide 
gas is always evolved. With more than St atoms of lead and longer 
boiling, a colourless solution of quadrobasic nitrite is obtained; and by 
boiling for a shorter time only, a pale yellow liquid, which on cooling 
deposits a mixture of the salts B, a and B, 6; these may be separated by 
boiling water, which extracts the latter. (Peligot.) If the salt be 
regarded as quadrobasic, the formula of its production may be as follows : 

3(PbO,NO*) + 5Pb = 2(4PbO, NO*) + NO* ; 

With regard to Peligot's assumption that the salt contains -f At. acid, it is 
not easy to devise a formula which shall express the mode of formation. 
Orange-yellow prisms which retain their water till heated above 100°. 
They dissolve in concentrated acetic acid without evolution of gas, pro- 
vided the acid be gradually added, so that no heating may take place. 
The yellow solution of 100 parts of this salt dissolves 27 parts of 
peroxide of lead, with decoloration of the liquid and formation of nitrate 
of lead-oxide. By decomposing the salt with barjrtarwater, we obtain 
nitrate and nitrite of buryta. The crystals dissolve in 1250 parts of cold 
and in 34 parts of boiling water. (Peligot.) 



154 



yPbO 








LEAD. 

Calculation 1. 
m .... 86-82 
92 .... 10-19 
27 .... 2-99 


Pdigc*.. 
86*64 


2N0* 
3HO 








10-41 

3-03 


7PbO, 


2N0* + 

4PbO.. 
NO* .. 
2HO.. 


3Aq. 


•••••••• 


903 


.... 10000 

Calculatio 

448 

46 

18 


10008 

II a. 

87-50 








« 


8-98 
3-52 




4PbO,NO* + 


2Aq« 


••■•••*• 


512 


10000 



Peligot fonnd 3*17 per cent, of nitrogeD^ which corresponds to 10*41 
hyponitric acid. (14 : 46=3-17 : 10*41.) — Berzelius, by boiling 1 part of 
lead-nitrate with 1^ pt. lead-foil and 50 water, for a long time, and 
leaving the liquid to cool, obtained sometimes crystals of the pale red 
salt A, a, sometimes brick-red needles. The latter are formed when the 
boiling is not continued long enough, and consist, according to Peligot, 
of the pale red salt A, a, and the orange-yellow salt B, a, which, being 
soluble in different degrees, may be partly separated by digestion in a 
quantity of water not sufficient to disBolve the whole. By heating 1 part 
of lead- nitrate with 1^ parts (2 At.) of lead and 50 of water, till the lead 
is completely dissolved. Berzelios obtained a solution which yielded 
brick-red scales on cooling, and, on evaporating the mother-liquid, the 
same salt was obtained in brick-red, fern-like tufts, together with the 
yellow salt B, 6. 

H According to Bromels, there are likewise two other orange-coloured 
salts formed by boiling lead-nitrate with metallic lead; viz. (1) a 
compound of a nitrate and a hyponitrate, composed of 4PbO,N0^4- 
3PbO,NO» + 3HO, or PbO,NO*-h6PbO,NO« + 3HO; this salt crjrstallizes 
in orange-red prisms destitute of lustre; (2) a compound of a nitrite and a 
hyponitrate, whose formula is 3PbO,NOH4PbO«NOH3HO, and which 
crystallizes in orange-red prisms more lustrous than the salt B, a, and 
having a greater number of facets. The analyses of the three orange^red 
salts, however, approach so near to each other that it is difficult to 
believe that the salts are really different, or to attribute the slight 
variations observed to anything out accidental impurity. The greatest 
differences in the amount of lead were between 86-02 and 87*72 per cent* 
{Comp. Gerhardt, Compt rend, trav.Chim, 6, 166.) IT 

6. Bibanc, — First obtained by Proust, who regarded it as a nitrate of a 
suboxide of lead; Berzelius regarded it as a bibasic nitrite of the protoxide. 
— An aqueous solution of 100 parts (1 At.) of lead-nitrate heated for 
some hours to a temperature been 70° and 75°, with 78 parts (rather 
more than 1 At.) of lead-foil, aoquires a yellow colour, and deposits 
yellow scales of this salt as it cools. The action begins between 50 and 
55°, but is quicker between 70° and 75®; above 80®, a portion of the 
salt is decomposed, with evolution of nitric oxide gas. On the first 
application of the heat, crystals of dinitrate of lead-oxide are likewise 
deposited. (Berzelius.) t'eligot takes 63 parts (1 At.) of lead to 100 
parts (1 At.) of the nitrate: 

PbO,NO» + Pb = 2PbO,N01 

If, from the presence of too mnoh lead, and from too lon^ boiling, the 
crystallized salt has become contaminated with orange-yellow scues of 
the salt B, a, Peligot treats it with a small quantity of hot water in 



HTPONITRATS OF LBAD-OXIDS. 155 

which the yellbir salt B^ h la more solnblei and leares it to orjrBtaUize.^:^ 
Cherreal boiLs the aqneous solution of lead-nitrate with ezeess of lead 
only till the liquid turns yellow; he states^ however, that this process 
does not yield a pure salt^ dinitrate of lead-oxide becoming mixed with 
it if the boiling be not oontinded long enoUffh^ and quadrobasio nitHte if 
it be kept up too long. According to Bereelius, 78 parts of lead and 100 
of nitrate, yield, after eomplete solution of the lead^ nothing but the 
yellow salt, quite unmixed with the brick-red saltj aocording to Feligot, 
on the contrary^ the salt B, a becomes mixed with it, eren when these 
proportions are used. — 2. If the vapours erolyed on heating fuming 
nitric acid are passed into water containing finely divided lead-oxide, the 
oxide turns white, and afterwards dissolves completely, forming a deep 
yellow liquid, which, on evaporation, yields a large quantity of silky 
scales of nitrite [or hjrponitrate?] of lead-oxide, together with a small 
quantity of nitrate. (Fritzsche, Ji pr, Chem, 19, 179.) 

Yellow, shining laminie and long flat needles. They blue reddened 
litmus (Berzelius), have a slightly sweet and astringent taste (Chevreul), 
and exhibit two axes of double refraction. (Herschel.) The salt does 
not part with its water till heated above lOO''. (Peligot.) Gives off a 

Sortion of its acid at 100°, and, at a strongelr heat, becomes pasty and 
arker in colour. (Chevreul.) When heated, it gives off aqueous acid 
and red vapours, but without fusing. (Berzelius.) Evolves red vapours 
when heated with stronger acids. (Berzelius, Chevreul.) It dissolv^es in 
cold, strong acetic acid, forming a yellow solution, and, without decom- 
position, if the acid be added graaually so as not to occasion rise of 
temperature. 100 parts of the salt dissolved in adetic acid dissolve 
44 parts of peroxide of lead. On decomposing it with baryta- water, 
nitrite and nitrate of baryta are obtained. (Peligot.) When the salt 
obtained by (1) is dissolved in boiling water, yellow laminsD separate out 
as the liquid cools; the mother-liquid, if evaporated and cooled, yields jpale 
yellow scales and finally white granular crystals together with yelloiV 
ones; the mother-liquid, after a portion of the lead-oxide has been 
precipitated by passing carbonic acid through it, is likewise found to 
contain nitrate of lead-oxide. (Chevreul.) — The salt dissolves in 80 parts 
of water at 25°, and in 10 '6 parts of boiling Water, the yellow solution is 
rendered turbid by carbohic acid. (Chevreul.) The solution, after yery 
long boiling with lead-oxide, which immediately becomes whitish and 
flocculent, yields the pale-red salt A, a. (Chevreul.) 

Pelifot Beneliufl* CheTreuI. 

2PbO 224 .... 80-28 .... 7990 .... 800 .... 8000 

NO^ 46 .... 16-50 .... 16-33 NO* 136 .... 1716 

HO 9 .... 3-22 .... 333 .... 6-4 .... 2-84 

2PbO,NO< + Aq. 279 .... 10000 Z 99*56 Z 1000 .... 10000 
Peligot found in the salt 4*97 per cent, of nitrogen. 

Berzelius decomposed the solution of the bibasic salt B, h with a quantity 
of sulphuric acid just sufficient to precipitate half the lead-oxide, and, by 
evaporating the yellow filtrate in vacuo, obtained lemon-yellow octo- 
hedrons containing 5*7 per cent, of water; these crystals he regarded as 
mononitrite of lead-oxide. This salt is regarded by Peligot as a mixture 
of mononitrite and mononitrate of lead-oxide. — Chevreul passed carbonic 
acid gas through the aqueous solution of the bibasic hyponitrate as long 
as lead-oxide was precipitated. The filtrate^ when evaporated, gave off 



156 LBAD. 

red vapoan, and yielded white needles of dinitrate of lead-oxide^ together 
with yellowish-white scales containing that salt^ and likewise the dini- 
trite [hjponitrate]; afterwards it yielded yellow octohedrons consisting 
of dinitrite [hyponitrate] and mononitrate of lead-oxide. 

H. Gerhardt regards the two salts just descrihed, not as hyponitrates, 
but as double salts composed of nitrates and nitrites. In fact, on adding 
a solution of nitrate of silrer-oxide to a solution of the bibasic salt just 
described, an immediate precipitate of nitrite of silyer-oxide is obtained. 
•—According to this yiew, the yellow scales first formed by the action of 
metallic lead on the mononitrate, are composed of dinitrite and dinitrate 
of lead-oxide; 

2(2PbO,NO«,HO) « 2PbO,NO»,HO + 2PbO,NO<,HO ; 

and their formation may be represented as follows : 

2(PbO,NO») + 2Pb + 2HO = 2PbO,NO»,HO + 2PbO,NO»,HO. 

If the action of the metallic lead be further continued, a fresh portion of 
nitrate is de- oxidized, and the result is the orange-yellow salt, which may 
likewise be regarded as a double salt more basic than the former; 

7PbO,2NO< = 4PbO,NO» + 3PbO,NO«. 

Finally, by the continued action of the lead, the subnitrate contained in 
these salts is reduced in its turn, and one or other of the subnitrites A, a, 
or A^ c, is obtained. (Compt rend, trav. Chim. 6, 168.) V 

G. Nitrate OF Lead-oxide, or Lbad-nitratr. — a. Sexhanc — ^Formed 
by precipitating the mononitrate with ammonia, and digesting the washed 
precipitate with that alkali for twelye hours. — ^White powder, haying a 
slightly astringent taste. — When moderately heated it giyes off water, 
and assumes a yellow colour, but becomes white again on cooling; when 
ignited it yields yellow pulyerulent protoxide of lead. It is nearly inso- 
luble in water. (Berzelius.) 



6PbO 


672 


... 
... 


91-43 
7-35 
1-22 


Beneliiu. 
90*80 


NO» 

HO 


54 

9 


7-37 
1-83 


6PbO,NO« + Aq. 


735 


... 


10000 


.... 100-00 



h, Terhasie. — Trinitrate, — Formed by precipitating a solution of the 
mononitrate with a slight excess of ammonia, digesting in a close yessel, 
adding more of the mononitrate in drops, digesting again, again dropping 
in the mononitrate, — and so on, till only a yery slight excess of ammonia 
remaius in the liquid, too small to be detected by its odour, and only 
recognizable by the fumes which it gives with hydrochloric acid. The 
precipitate is then washed and dried out of contact of air. — White 
powder. When gently heated, it gives off water and turns yellow, but 
becomes white again on cooling ; when more strongly heated it leaves 
protoxide of lead in the form of a lemon-yellow powder. Slightly soluble 
m pure water, but insoluble in water containing in solution various salts 
which do not exert a decomposing action on the compound. (Bcrzelius.) 

Benelius. 

6PbO 672 ... 83-27 8298 

2NO* 108 ... 13-38 1352 

3HO 27 ... 3*35 3*50 



2(3PbO,NO*; + 3Aq. 807 ... lOO'OO 100-00 



LEAD-NITRATE. 167 

e. Bibasie.'^DinUraU. — 1. By boiling 1 ])art of the mononitrate with 
1 part of lead-oxide and with water, then filtering, and leaving the solution 
to crystallize. (Chevreul, yinn. Chim, 83, 70.) — 2. By heating the mono- 
nitrate with white lead and water, filtering at a boiling heat, and leaving 
the liquid to oool. The carbonic acid is evolved as rapidly as if free nitric 
acid were present No salt containing a larger excess of base is formed, 
even if the white lead is in great excess; for the dinitrate does not 
decompose white-lead. (Pelouze, Ann. Chim, Phys, 79, 107; also J. pr. 
Ckem, 25, 480.) — 3. By precipitating the mononitrate with a quantity of 
ammonia not sufficient to throw down the whole of the lead-oxide. (Ber- 
selius, GUb. 46, 142.) — 4. When the mononitrate is boiled with zinc-oxide, 
the bibasic salt separates from the solution. (Persoz, Ann, Chim, Fhy$, 
58, 191.) — As the hot aqueous solution cools, the salt separates in white 
grains and pearly laminas and needles, having a slightly sweet and 
astringent taste. These crystals, wben gently ignited, leave red-lead, which, 
at a higher temperature is converted into the yellow protoxide. (Ber- 
zelins, l^ogg. 19, 312.) At 100° they lose but little water, not giving oflT 
the whole till heated to between 160° and 190°, and slowly even then. 
At 200° the salt turns yellow and gives off red vapours. (Pelouze.) — 
Carbonic acid robs it of half its lead-oxide. (Chevreul.) It is but very 
slightly soluble in cold water, much more soluble in hot water. (Berzelins, 
Pelouze.) 

CaieHlaiian 1. Benelins. Cherrenl. 

2PbO 224 ... 80-58 805 8014 

NO* 54 .... 19-42 19-5 1986 

2PbO,NO» 278 ... lOO'OO ~. 1000 ~, lOO'^O 



2FbO 
N0».. 
HO .. 



Caleuhium 2. 


Pelouse. 


224 ... 78-05 


78-0 


54 .... 18-81 


19-0 


9 ... 314 


.... «S*1 



2PbO,NO* + Aq. 287 ... 100-00 100-1 

According to Berzelius and Chevreul, the crystals are anhydrous, or at 
least contain nothing but water of decrepitation, which escapes with 
violence when they are heated; but according to Persoz and Pelouze, they 
contain 1 atom of crystallization-water. 

€L M(monitroUe,^~W9xm dilute nitric acid dissolves lead but slowly, 
with evolution of nitrous gas; the same compound is obtained by dissolv- 
ing the oxide. — The salt belongs to the regular system. Fig. 1, 2, 4, 13, 
and 20; also in macle-crystals, like those of spinelle. (Haidinger, Edinb» 
J* €f Se. 1, 102; Wackemagel, Kattn, Arch, 5, 295.) Specific mvity, 
4*3998. (Karsten.) The crystals exhibit a conchoidal, not a laminar 
fracture; they are harder than alum, white, with a waxy lustre. (Hai- 
dinger.) 

Dobereioer. Svanberg. Berzelias. Cherreol. 

PbO 112 .... 67-4 .... 67-6 .... 67403 .... 67-2225 .... 67 

NO» 54 .... 32-6 .... 32-4 .... 32-597 .... 327775 .... 33 

PbO,NO» 166 .... 1000 .... 100-0 .... 100-000 .... 100*0000 .... 100 

The salt decrepitates at a red heat, giving off oxygen gas and hypo- 
nitric acid, and leaving protoxide of lead. When it is ignited in a silver 
crucible, not sufficiently to decompose it, but till it becomes covered with 
a metallic film, and the mass when cool is boiled with water, the filtrate, 
after cooling, deposits dinitrate of lead-oxide, and the motlier-liquid, 



158 . LBAD. 

vbaB erapOMtad dapoeits metallio lead, while nitfaie of lead-oxido 
remains in solution. (Hess, Pogg, 12, 262,^ Detonates with brilliant 
sparks when thrown on red-hot coals; shghtly when triturated with 
sulphur. The inflammability of tinder, blotting paper, &c., is greatly 
increased by soaking them in a dilute solution of this salt. — It is perma- 
nent in the lur: dissolves in water producing a great degree of cold. (H. 
Bose.) One part of the salt dissolves in 1*989 parts of water at 17*5°, 
forming a liquid of specific gravity 1*3978 (Karsteu), in 1*707 water at 
22*3^; and 1-585 water at 247"". (Kopp.V The specific gravity of a 
solution saturated at 8° is 1*372. (Anthon.) Nitric acid precipitates the 
salt from its aqueous solution. (Braconnot, Ann, Chim. Phys. 52, 288.) 
Insoluble in alcohoL When present in excess, it exhibits a tendency to 
combine with the insoluble lead-salt formed by precipitation. (Berzelius.) 

D. BoronUride of Lead% — Cyanide of lead ignited with boracic 
acid in the manner described (III. 70) yields a mass, which, after wash- 
ing, gives off ammonia when treated with hydrate of potash. 

E. Phosphonitrate of Lead-oxidb. — On pouring phosphoric acid 
into an aqueous solution of lead-nitrate, or evaporating a solution of lead- 
phosphate in nitric acid, crystalline grains are separated, which may be 
dried by pressure between bibulous paper : they contain 2 atoms of 
monophosphate of lead-oxide combined with I atom of nitrate; and, when 
heated, are converted, with evolution of nitrous acid vapours, into triphos- 
phate of lead-oxide. Cold water extracts a small quantity of the nitrate 
contained in these crystals, and boiling water nearly the whole. (Ber- 
zelius, Ann. Chim, Phys, 2, 161.) A solution of lead-phospfaate in warm 
nitric acid deposits, on cooling, pure nitrate of lead-oxide crystallized in 
octohedrons elongated into four-sided prisms. (Dujardin, J, pr. Chem, 
15, 309.) 

IT P. AzoPHOsPHATE OP Lead-oxide. — 3PbO,PNO*-h5Aq. — Formed 
by adding a soluble lead-salt to a neutral aqueous solution of the salts 
obtained by treating chlorophosphide of nitrogen (II. 474) with alcohol 
and ammonia. — White granular powder, which is decomposed by am- 
monia. — When heated it is decomposed in a similar manner to the 
iron-salt (q. v.) (Gladstone, Chtm. Soc. Qu. J. III. 149.) fT 

G. Nitrate op Lbad-oxidb with Fluoride op Lead. — Flooride of 
lead precipitated from a solution of the nitrate by fluoride of sodium 
contains nitrate of lead in a state of admixture, and difficult to remove 
by water. (Berzelius.) 

H. Plumbite op Ammonia. — I part of litharge dissolves by digestion 
in 6 parts of an aqueous solution of caustic ammonia or carbonate of 
ammonia, forming a deep yellow, non-crystallizable liquid. (Karsten.) 
The solution is turbid. (Wittstein, Repert, 63, 329.) 

I. Hyposulphite op Lead-oxide and Ammonia. — Formed by dis- 
solving h^osulphite of lead-oxide in a moderately strong solution of 
hyposulphite of ammonia — the mixture being shaken and gently heated 
— and leaving the solution to crystallise by evaporation in the air. At a 
boiling heat, sulphide of lead would be precipitated; a small quantity of 
this compound is formed even during iq>ontaneous evi^oration. — Trans- 



AMMONIO-CHLORIDB OP LEAD. 109 

parent and oolonrless crystals belonging to the right prismatic system. 
Fig, 55 nearly; u : tt^=104°; * : <=104**, SC. — Dissolves easily and com- 
pletely in cold water. The solation, i^ter standing for a few minutes, or 
more qnickly if heated, deposits hyposulphite of lead-oxide in spangles, 
which, if heat has been applied, are mixed with sulphide of lead; sul- 
phates added to the solution do not produce an immediate turbidity. 
(Rammelsberg, Pogg, 56, 312.) 

CryttaUized. Raminelsberg. 

2NH» 34 .... 10-16 9-79 

PbO 112 .... 33-43 34-45 

3S20» 144 .... 42-99 

6HO 45 .... 13-43 

2(NH*0, &QP) + PbO,S«0» + 3Aq, 335 .... 10000 

K. Sulphate of Lead-oxidb astd AMMONiA.^-Sulphate of lead- 
oxide dissolves abundantly in hot aqueous sulphate of ammonia, in con- 
sequence of the formation of a double salt, which, however, separates on 
cooling. The compound may be prepared by precipitating a moderately 
strong solution of lead-acetate with dilute sulphuric acid in excess- 
neutralizing with ammonia— heating nearly to the boiling point till the 
precipitate is completely re-dissolved — ^and leavipg the solution to crys- 
tallize by cooling. If the precipitate does not re-dissolve completely, 
more sulphate of ammonia must be added. If no crystals separate on 
coolinff, the liquid must be heated again, and sulphuric acid added till 
turbidity begins to show itself. The doubb salt appears to form with 
peculiar facility in a liquid containing a large quantity of acetate of 
ammonia. — Small, transparent, and colourless crystals. — The salt, when 
ignited, yields a sublimate of sulphite of ammonia, and a residue of 69*8 
per cent, of lead -sulphate. In water the crystals immediately become 
milk-white, the water dissolving out the sulphate of ammonia aud, after 
boiling, leaving 69*2 per cent, of lead-sulphate. (Wohler & Litton, Ann, 
Fharm. 43, 126.) 

Litton. 

NH40,80» 66 .... 30-28 303 

PbO,B0» 152 .... 69-72 69'8 

NH*0,Y03 + PbO,SO» 218 .... 100-00 ~. 1001 

L. Ammonio-iodide of Lead. — 100 parts of iodide of lead absorb 
7'19 parts (1 At.) of ammonia. — The white compound, when exposed to 
the air, gives off the whole of its ammonia. Under water, it remains 
white, but is decomposed into hydriodate of ammonia which dissolves, 
and protoxide of lead mixed with a small quantity of iodide. (Rammels- 
berg, Pogg, 48, 166.) — Iodide of lead immersed in dilute ammonia turns 
whitish, and, in a few days, is converted into a white magma, which may 
be dried in the air without decomposition, but, when heated, is resolved 
into ammoniacal gas and iodide of lea<l. (Laboure, JT. J, Pluirni, 4, 
328.) 

M. IoDi0E OF Lead and AMBtONiuM. — Hydriodate of ammonia in 
excess forms with nitrate of lead oxide a white precipit9,te, which is 
decomposed by a large quantity of water. (P. Boullay.) 

N. Ammonio-chloridb of Lead. — 100 parts of chloride of lead 
absorb very slowly and with slight intumescence, 9*31 parts (| At) of 
ammoniacal gas. (H. Rose, P^g. 20, 157.) 



160 LBAD. 

0. Chloridb op LfeAD AND AMMONIUM. — a. Becquerel obtained this 
coinpottDd crystallized in needles by galvanic action t (I, 401.)---^. An 
aqueous mixture of chloride of lead and sal-ammoniac is not precipitated 
by sulphuric acid. (Th^nard.) 



Lead and Potassium. 

. r A. Allot of Lead and Potassium. — 4 volumes of lead-filings com- 
bine at the melting x^int of lead with 1 volume of potassium, forming a 
brittle, easily fusible alloy, which exhibits a fine-grained fracture and 
effervesces strongly with water, but still more with aqueous acids. (Gray- 
Lussac & Thenard.)~-By reducing TOO parts of lead-oxide at a strong red 
heat with 100 parts of thoroughly burnt or 60 parts of partially burnt 
tartar, a grey, brittle lead is obtained, which has a fibrous texture and 
alkaline taste, and, according to Vauquelin {Schw. 21, 222), does not 
effervesce with water; accordmg to Serullas, however {Ann, Chim, Fhys, 
21, 200), it effervesces slowly. 

B. Plumbitb of Potash. — Protoxide of Lead teith Potath. — ^Litharge 
dissolves in hot potash-ley, forming a yellow liquid which does not 
crystallize; carbonate of potash acts in a similar manner. (Karsten, Scher. 
J. 5, 575.) — When white lead is boiled with potash-ley, a colourless 
solution is obtained; and this solution, on cooling, yields small, silver- 
white, crystalline scales which acquire a grey tarnish by exposure to the 
air. The remaining liquid forms, on evaporation, a brownish-red, scaly, 
shining mass, which re-dissolves in water, with the exception of a few 
shining scarlet scales. Metallic lead is precipitated from the solution by 
phosphorus and zinc, but not by iron. Tin immersed in a solution of 
plumbite of potash, throws down all the lead: a case of reciprocal affinity. 
(Fischer, Po^g. 9, 263.) 

C. Plumbate of Potash. — Peroxide of Lead with Poto«&.— Formed by 
fusing peroxide of lead with excess of potash-hydrate in a silver crucible, 
dissolving in water, and evaporating; the compound is then obtained in 
definite crystals. It may likewise be formed by fusing potash-hydrate 
with the yellow protoxide, which is then converted into the peroxide by 
absorbing oxygen from the air. — This salt dissolves without decomposi- 
tion in caustic potash, but, in contact with pure water, it turns red and is 
resolved into aqueous potash and precipitated peroxide of lead. (Fremy^ 
-y. J. Pharm. 3, 32.) 

D. Hyposulphite of Lead-oxide and Potash. — Formed by dissolv- 
ing hyposulphite of lead-oxide, with agitation, in warm aqueous hypo- 
sulphite of potash, and leaving the solution to crystallize by cooling. If 
the liquid is tolerably concentrated, it solidifies in a white mass, by the 
formation of extremely delicate, silky needles, which mnst be pressed to 
free them from the mother-liquid, that liquid always containing a large 
quantity of free potash-salt. — The double salt, when heated out of con- 
tact of air, gives off sulphurous acid and sulphur, and leaves a residue 
amounting to 77 '39 per cent., and consisting of sulphide of potassium, 
sulphate of potash, sulphide of lead, and sulphate of lead-oxide. It dis- 
solves in water, with partial separation of hyposulphite of lead-oxide in 
shining spanj4le8. The solution is not clouded by sulphates, and after 



lODIDB OF LEAD AND POTASSIUM* 161 

some time only, by sulphnric acid, the precipitate then formed consisting 
of sdphar and sulphate of lead-oxide. (Rammelsberg, Pogg, 56, 310.) 



2K0 
PbO 

zsHy 

2HO 



Crytiallized. 


Rammelsberg* 


94-4 ... 25-62 


26-29 


1120 ... 30-40 


28-97 


1440 ... 3909 




180 ... 4-89 





2(KO,S«0») + PbO,S»0» + 2Aq. 3684 ... 100-00 

E. Sulphate of Lead-oxide and Potash. — Precipitated when 
sngar-of-lead is mixed with sulphate of potash. It appears to contain 
sulphate of lead-oxide and sulphate of potash in equal numbers of atoms; 
but the longer it is boiled with water, and the greater quantity of water 
present, the greater is the quantity of sulphate of potash dissolved out of 
it. (Trommsdorff, TascJienb, 1825, 1.) 

P. Iodide op Lead and Potassium. — a. 2KI,PbP. — Separates in 
yellowish, silky crystals, on pouring a solution of lead-nitrate into an 
excess of concentrated aqueous iodide of potassium. 

Boullay. 

2KI 330-4 ... 58-96 64 

Pbl 230-0 ... 41-04 36 

2KI,PbI 560-4 ... 100-00 100 

h. 2KI,3PbI. — 1. The mother-liquid poured off from a yields yellow 
prisms after a few days. — 2. The mother-liquid poured off from the yellow 

{krisms and mixed with alcohol, deposits white crystals haying a silky 
ustre. — If water be added instead of alcohol, yellow iodide of lead is 
separated at first, but it is soon converted into the white salt 6. — 3. When 
nitrate of lead-oxide is poured into a less concentrated solution of iodide 
of potassium, a yellow precipitate is formed, but is soon converted into 
white silky needles, which thicken the liquid. On heating the mixture, 
yellow iodide of lead is formed, which still retains the form of the 
needles, and, on cooling, is reconverted into white iodide of lead and 
potassium. (P. Boullay.) — This salt is formed, together with carbonate 
of lead-oxide, on boiling iodide of lead with a concentrated solution of 
carbonate of potash. (Berthemot, J. Fhaifit. 13, 311.) Becquerel ob- 
tained it, by electrolytic action, in white silky needles. (I, 401.) — The 
needles are permanent in the air. When heated, they turn yellow, give 
off a small quantity of water, and fuse into a red liquid, which, on cooling, 
solidifies in a yellow mass. Heated with sulphnric acid, they deposit, first 
iodide of lead, and then sulphate of lead-oxide. Water separates iodide 
of lead from the cry«}tals, dissolving out the iodide of potassium, together 
with a small quantity of iodide of lead, which, however, when a large 
quantity of water is used, does not exceed a mere trace. Cold alcohol 
Has no action on the crystals; hot alcohol leaves iodide of lead undissolved 
and deposits the salt h on cooling, iodide of potassium remaining in 
solution. (Boullay, J, Pharm. 12, 639; also Ann, Chim, Phys. 34, 366.) 

Boullay. 



2KI 

3PbI 


330-4 ... 32-38 
6900 ... 67-62 


'(1) 
30*5 

69-5 


(2) 
... 31 
... 69 


(3)- 
... 30-25 

... 69-75 


2KI,3PbI ... 


1020-4 .... 100-00 


.... 100-0 


... 100 


... 100-00 



The crystals (3) likewise contain 3 per cent, of water. (Boullay.) 

VOL. T. M 



162 I^AD, 

G. Bromidb of Leab and Potabsium . — When conoentrated solutiona 
of nitrate of lead-oxide and bromide of potassium, the latter somewhat in. 
excess^ are mixed, filtered, and evaporated, small octohedrons are pro- 
duced ^ soluble without decomposition in a very small quantity of water, 
but decomposed by a larger quantity, with separation of bromide of lead. 
(Lowig.) 

Crystallized. Lowig;. Or i 

K 39-2 ... 1300 „. 12-90 KBr 117-6 ... 39-2 

Pb 1040 ... 34-66 ... 3638 PbBr 1824 ... GOB 

2Br 166-8 ... 52-26 ... 50-72 



KBr,PbBr 8000 ... 10000 ... 10000 3000 ... 1000 



Lead and Sodium. 

A. AlXiOY op Lbad and Sodium. — 4 Tolumes of lead-filings heated 
with 1 volume of sodium to the melting point of lead, fuse with evolution 
of heat, but not of light, and form a bluish-grey, slightly extensible, 
fine grained alloy, which melts at the samie temperature as lead, oxidizes 
in the air, and efi*ervesces slightly in water, but strongly in aqueous 
acids. — 3 volumes of lead-filings form, with 1 volume of sodium, a brittle, 
easily oxidable alloy. ( Gay-Lussac & Th6nard.} An alloy may also be 
formed by igniting lead with charred soap. 

B. Plumbttb op Soda. — Litharge dissolves in a boiling aqneona 
solution of caustic soda or carbonate of soda, forming a yellow liquid. 
(Karsten.) 

C. Plumbate op Soda. — Analogous to plumbate of potash. (Fremy.) 

D. Carbonate op Lead-oxidb and Soda. * — When nitrate of lead- 
oxide is precipitated by carbonate of soda, the precipitate boiled in the 
alkaline liquid, and afterwards washed and dried at 160^, this precipitate 
evolves, on ignition, 15-1 8/1 percent, of carbonic acid, and is therefore 
composed of NaO,CO»-f 4(PbO,CO»).— (Berselius, Pogg, 47, 199.) 

E. SuLPHTDB OP Lead and Sodium. — 90 parts of lead-sulphate 
heated to whiteness in a charcoal crucible with 10 parts of dry sulphate 
of soda, yield 3*5 parts of metallic lead, and 19 parts of a metallic sul- 
phide containing from 20 to 25 per cent, of sulphide of sodium. Sulphide 
of lead and sodium is a shining, lead-grey, brittle substance, exhibiting a 
close fracture. Water dissolves out the sulphide of sodium from it, and 
leaves a eompound of one atom of sulphur with more than one atom of 
lead, (Berthier, Ann, Chim, Fhys. 22, 215.) 

F. Hyposulphitb op Lbad-oxidb and Soda. — Formed by adding 
acetate of lead-oxide to aqueous hyposulphite of soda, as long as the 
precipitated hyposulphite of lead-oxide re-aissoIVes on agitation — precipi- 
tating the double salt from the filtrate with alcohol — and washing the 
precipitate with alcohul. It may also be obtained by dissolving chloride 
of lead in hyposulphite of soda. — The precipitate becomes crystalline 
after awhile. It dissolves sparingly in water, but very freely in aqueous 
acetate of soda. (Lenz, Ann, Pkarm, 40, 98.) It resembles the potash- 
salt in eyeiy respect. (Bammelsberg, Pogg, ^Q, 311.) 



LEAD AND BARIUM. 163 

Lenz. 

2NaO 62-4 ... 19*60 1909 

PbO 1120 ... 3518 35-84 

3fflOg 144 ... 45»22 4611 

2(NaO,S20») + PbO,SW 318*4 ... 10000 ~, 10104 

G. Sulphate of Lead-oxide and Soda. — Solphfito of lead-oxide an(i 
snlpbate of soda in equal numbers of atoms fuse at a red heat, forming a 
liquid as thin as water, and yield, on cooling, an opaque mass, having an 
uneven, non-crystalline fracture. (Berthier, Ann. Chim. Fhyi, 38, 256.) 

H. Iodide of Lead and Sodium. — ^Beoquerel obtained ibia compound, 
by the electrolytic method, in needles having a silky lustre. (I, 401.) 

I. Bromide of Lead and Sodium.— r May be prepared in the same 
way as the potassium compound. Crystallizes in prisms. Deoomposible 
by water. (Lowig.) 

K. Chloride of Lead and Sodium. — Obtained by Beequerel in 
tetrahedrons, by the electrolytic method. (I, 401.) 



Lead and Barium. 

A. Plumbite op Baryta. — ^Boiling baryta-water fbims with lead- 
oxide a deep yellow solution, which, on evaporation, leaves its two consti- 
tuents separate [in the form of carbonates ?J. (Karateu.) 

B. Suf^PHiDE OF Lead and Barium. — 15 parts of sulphide of lead 
heated to whiteness in a charcoal crucible with 15 parts of sulphate of 
baryta yield 17 pff rts of sulphide of lead and barium, sulphide of lead 
being sublimed and a small Quantity of metallic lead reduced. — This com- 
pound is of a dingy red colour, without metallic lustre, and of shining 
laminar fracture. Water extracts the sulphide of barium and leaves 10 
per cent, of sulphide of lead. (Berthler.) — When sulphide of lead and 
sulphide of barinra, in equal numbers of atoms, are heated to whiteness in 
a charcoal crucible, the greater part of the lead-sulphide volatilizes, and 
there remains a well fused, blistered mixture, having a brown-red colour 
and waxy lustre, and yielding a red powder. (Foumet.) 

C. Hyposulphite op Lead-oxide and Baryta. — Hyposulphite of 
lead-oxide and potash, mixed with acetate of baryta, throws down, after 
a few minutes, a precipitate consisting of the barytic double salt. The 
precipitate, however, is mixed with free hypos^lphite of baryta, because 
the solution of the potassic double salt contains free hyposulphite of 
potash. The digestion of hyposulphite of baryta with water and hypo- 
sulphite of lead-oxide dees not form a solution. (Rammelsberg, Pogg, 
56, 313.) 

D. Chloride of Lead and BARiitM.— Obtained by tlte slectrolytic 
method in crystals having a silky lustre* (Becquerel^ I. 401.) 



m2 



164 LEAD. 



Lead and Strontium. 

Hyposulphite of Lead-oxide and Strontia.— Hjrposulphite of 
lead-oxide dissolves abundantly in aqueous hyposulphite of stroutia; the 
solution^ however, yields do crystals, but deposits a syrup on the 
addition of alcohol. (Rammelsberg.) 

Lead and Calcium. 

A. Plumbite of Lime.*— Heated lime-water dissolves lead-oxide, form- 
ing a yellow solution. On evaporating the liquid, the plumbite of lime 
crystallizes in small spiculae, which have a caustic taste, and are slightly 
soluble in water, forming a solution which blackens wool, nails, and 
horn. (Karsten, Scher. J. 5, 575; Berthollet, Ann, Chim. 1, 52.) 

B. Carbonate op Lead-oxide and Lime. — Plumho-<xdcite, — Obtuse 
rhombohedrons, Fig, 141; r* : r*=:104° 53' (Brewster). Specific gravity 
2 '824. Softer than calcspar; transparent, with a pearly lustre. — Contains 
92*2 per cent, of carbonate of lime, 7*8 p. c. carbonate of lead-oxide, and 
a trace of ferric oxide. Decrepitates in the fire, and by continued ignition 
acquires a brownish or reddish colour. With carbonate of soda on 
charcoal before the blowpipe, it yields a white enamel but no globules of 
lead. (Johnston, N. Edinh. J. of Sc, 6, 79; also Pogg. 25, 312.) 

C. Hyposulphite of Lead-oxide and Lime. — From a solution of 
hyposulphite of lead-oxide in aqueous hyposulphite of lime, which is not 
rendered turbid by the addition of sulphates, alcohol throws down the 
double salt in white crystalline granules, partially decomposible by 
water. (Rammelsberg.) 

CryttaUized. Rammelsberg. 

2CaO 56 .... 16-09 17-00 

PbO 112 .... 32-18 30-29 

3S20» 144 .... 41-38 

4H0 36 .... 10-35 

2{CaO,S«0«) + PbO,S«0« + 4 Aq. 348 .... 10000 

D. Phosphate of Lead-oxide and Lime with Chloride of Lead. 
'—NvMierite. — This mineral occurs in connexion with Pyromorphite 
(p. 149). Very obtuse rhombohedrons. Specific gravity 5*0415. Yel- 
lowish, greenish, or greyish, with a faint waxy lustre. After fusion 
before the blowpipe, it solidifies into a whitish, angular enamel. Forms 
a yellowish glass with borax. Dissolves readily and without efifervedcence 
in nitric acid. Contains: PbCl 7-65,— CaO 12-30,— PbO 46*50,— 
FeO 2-44,— cPO* 19*80,— AsO* 406,— quartz 7*20 (less 05). (G. Bar- 
ruel, Ann. Chim, Phys, 62, 217; also J, pr, Chem. 10, 10.) 

E. Sulphate of Lead-oxide with Fluou-spar. — a. One atom of 
fluor-spar with one atom of lead-sulphate fuses very easily to a thin 
liquid, which, on cooling, yields a dense, spongy mass, of uneven, non- 
crystalline fracture. — 6. 1 At. fluor-spar with 2 At. lead-sulphate: Fuses 
just as readily and forms as thin a liquid as the above, and yields a 
dense, yellowish-white, stony mass.— c. 1 At. fluor-spar with 4 At. 
lead-sulphate: Fuses less completely, and forms yellowish, blistered. 



LEAD AND $ILIC1UM. 165 

cruinbling^ granular, bat not crystalline mass.'^^f. 1 At. fluor-spar, 1 At* 
lead-sulphate, and 1 At. lime : This mixture yields sulphate of lime and 
uncombined lead-oxide; fuses very easily to a very thin liquid, which, 
on cooling, forms a pale-grey, crystalline-laminar mass. — e, 4 parts of 
fluor-spar, 5 of heavy-spar, 6 of ignited gypsum, and 5 of lead-sulphate : 
Fuses perfectly at an incipient white heat and forms a thin liquid. 
Dense white enamel, having an uneven fracture. (Berthier, Ann. Chim, 
Fhys. 43, 298.) 

Lead and Aluminum, 

Phosphate op Lead-oxide with Htdrate op Alumina.— ^yc?roi« 
Aluminate of Lead^ PUyrnhgomme, BleigummL — Amorphous; harder than 
fluor-spar; of conchoidal fracture; yellowish-brown; translucent. When 
heated, it decrepitates strongly, gives off water, turns white, swells up, 
and fuses partially if urged by a strong blast. With carbonate of 
soda on charcoal, it yields globules of lead. Assumes a blue colour 
when ignited with nitrate of cobalt. Dissolves in nitric acid, (Berzelius, 
Schw. 27,65; Jahresber, 21, 214; Dufr^noy, Ann. Ckim. Fhys. 59, 440; 
also J, pr. Chem. 7, 163; Damour, Ann. Mines. Ser. 3, 17, 191; also 

J. pr. Chem. 21, 126.) 

Berzelius, Berzelius. Dufr^noy. 

PlombffOmme, Hnelgoet. Hnelgoet. NoMi&re. 

3PbO 336-0 .... 38-28 .... 3510 .... 40-14 .... 4342 

PO« 71-4 .... 814 .... 806 .... .... 1-89 

6AP05 308-4 .... 35-13 .... 3432 .... 37-00 .... 34-23 

18HO 162-0 .... 18-45 .... 18-70 .... 18'80 .... 1614 

CaO .... .... 0-80] 

Pe«0» .... .... 0-20> .... 1-80 

MOO ..., *..• J 

PbCl .... .... 2-27 8eO» 0-60 .... 2-11 

SO» .^ .... 0-30 SCy 0-20 

6(APO»,3HO) + 3PbO,PO» 8778 .... 100-00 .... 99*75 .... 98-54 .... 9779 



Lead and Silicium. 

A. Silicide of Lead. — The two metals fuse together before the 
blowpipe and form a malleable alloy, which, when dissolved^ in acids^ 
leaves a residue of silica. (Berzelius, Fogg. 1, 220.) 

B. Silicate op Lead-oxide, or Lead-silicate. — a. Silica fuses with 
lead-oxide to a yellow-glass. Glass formed of equal parts of lead-oxide 
and silica does not become dull in the air of a town (as from the action of 
sulphuretted hydrogen, which might form sulphide of lead); nor even 
when 3 parts more of lead-oxide are added to 8 parts of the glass; but 
the tarnishing takes place if 8 parts of the glass are fused with 1 part of 
potash. (Faraday, Fogg, 18, 568.) Lead-oxide attacks earthen crucibles 
when fused in them.— ^. Silico-fluoride of lead yields with ammonia a 
precipitate of lead-silicate. 

C. BoRosiLiCATE OF Lead-oxide. — 112 parts of lead-oxide yield 
with 16 parts of silica and 24 of boracic acid a yellow glass, of 
specific gravity 6*44, which fuses less easily than borate of lead-oxide 
(p. 128) but more easily than flint-glass, and is strongly tarnished by 
immersion in hydrosulphuric acid gas. (Faraday.) 



166 LEAD. 

D. SiLTCOFiTTOiiiDB OF Lead. — PbF,8iP.— A flolution t)f lead-oxide 
In hjrdroflttodilicic acid dries up to a translacent gtitn, haying the taste of 
other lead-8alts> and re-dissolving perfectly in water. (Benseliu.) 

E. SiLTCATis OF ' Leaim)xide AND AK Alkalt. — a. Lead-ffloss.-^ 
Lead-oxide forms, with silica and potash or soda, a vitreous'mass, which is 
distingaished from other kinds of glass by its greater density, refracting 
power, softness, and fusibility, and has so much the greater tendency to 
become tarnished in impure air with sulphide of lead, as it is richer in 
lead-oxide and more finely divided. A large quantity of lead-oxide 
colours it yellow, and the presence of metallic lead (or the suboxide) 
gives it a green tint: Flint-ghisSy Mainzer Fluss, Glazing, (III. 380, 
381.) 

h. Containing a larger proportion of potash, — The aqneons solntion of 
soluble glass (III. 371) if agitated with lead-oxide, takes npa portion of 
that substance, slowly at ordinary temperatures, bnt more quickly when 
heated, and is thereby converted into a stiff jelly, which, when exposed 
to the air, dries up to an opalescent mass. (Fuchs, Kastn. Arch, 5, 401.) 

F. Silicate op Zirconia and Lead-oxide.— -a. 2PbO,2ZrO,SiO'. — 
91*8 parts (1 At.) of zircon fuse with 224 parts (2 At.) of lead-oxide, 
forming a yellow, translucent, dense mass, having a waxy lustre and 
resembling gamboge. — 6. PbO,2ZrO,SiO*. — 91 '8 parts (I At.) of zircon 
soften when heated with 112 parts (I At.) of lead-oxide and form a stiff 
paste, which solidifies in a homogeneous, waxy, opaque mass. Both these 
compounds are easily attacked by acids. (Berth ier, Ann, Chim, Fkys, 
59, 193.) 

Lead and Titanium. 

Fluoride of Titanium and Lead. — ^Small colourless crystals, which 
taste sour at first, but afterwards sweet and astringent, and dissolve 
easily in water without decomposing. (Berzelius, Fogg, 4, 5.) 

Lead and Tantalum. 

J'luorid^ of Tantalum and Lead. — ^DiflScultly «olaWe in irik^^ 
(Berzelius.) 

Lead and Tungsten. 

A. TuNGSTiDB OF Lead. — Formed by exposing a mixtare of lead 
and tongstic acid to a very intense heat in a charcoal crucible. — ^Dark 
brown, with a faint Instre, spongy, and very ductile. (De Luyart.) 



B. Tungstate op Lead-oxide, or Lead-tungstate. — a. Mono- 
tungstate, — Found native, as Scheelitine, Belongs to the square prismatie 
system; isomorphous with tungstate of lime (Kobell, Schw. 64, 410). and 
with molybdate of lead-oxide (A. Levy, Ann, Fhil. 28, 364; also Fogg, 
8, 5 J 3); Pigs, 24, 28, 32, 35, with truncation of the edges between e and e'; 
« : c^= 13r 30'; « : e^ = 154° 36" (Levy). Cleavage parallel to p and e. 
(Breitliaupt.) Specific gravity 8*0. Harder than gypsum. Colourless 
or brownish-white; transparent or translucent, with a waxy Instre. 
Fuses before the blowpipe, covering the charcoal with a deposit of lead- 



LEAD AND MOLYBDENUM. Hi 

bti je, <wd, d& ooolihg^ solidifies in the form of a dfttk Clrystalline f lobtile. 
With borax it jields a colonrlesa glass in the enter flame, and in the 
inner, a yellowish glass, which becomes grey and opaque on cooling; if 
the fusion with borax be continued for a longer lime, lead lis volatilized, 
and a clear dark-red glass is formed. With microcosmio salt, thtli 
tnineral forms a colourless glass in the outer flame, and a bine glasd in 
the inner. With carbonate of soda on charcoal, it yields globules of 
lead. Dissolves in nitric acid, with separatio)! of yellow tungstio acid. 

When a lead-salt is precipitated with monotungstate of potash, a 
white anhydrous powder is obtained, which when heated, first turns grey 
and then yellowish, fuses at a red heat, and solidifies in a crystalline 
mass on cooling. Insoluble in water and cold nitric acid, but soluble in 
caustic potash. (Anthon, J.pr. Ckem, 9, 342.) 

6. Bitun^pttate. — Formed by precipitating nitrate of load-oxide with 
bitungstate of ammonia. — White powder, insoluble in water. (Berzelins.) 

Lampadins. Anthon. 

Monotungstate . native, artificial. 

PbO 112 .... 48-2« 48-25 .... 48*4 

W03 1 20 .... &i-7g 5175 .... 51-« 

PbO,WO» 232 .... 10000 10000 .... 1000 

Bitungstate, Bertelivs. 

PbO 112 .... 31-8 28-58 

2W03 240 .... 68-2 7142 

PbO,2W0» 352 .... 100-0 lOO'OO 

D. StrtPHOTUNosTAtB OP Lead,— PbS, WS». By mixing B«lpho- 
tnngstal^e of t)otas8ium with a lead-salt. Dark brown precipitaite, almost 
black when collected. If a lead-salt be precipitated by the compound 
of snlphotungstate of potassium with tungstate of potash (IV, 40), the 
Resulting precipitate is of a dingy yellow colour. (Berzelins.) 

LsAD AND Molybdenum. 

MoLYBDiDE OP Lead. — Lead alloyed with a small quantity of 
molvbdenum is whiter than pure lead, hard, and somewhat malleable; 
with a larger quantity of molybdenum it forms a black, brittle mass. 
(Hjelm.) 

B. MoLYBDATB OP Lead-oxide, or Lead-molybdatb. — Occurs in the 
form of Ydl<no Lead-ore, Melinme (Gelbhlden), Prepared artificially by 
J)recipitating nitrate of lead-oxide with monomolybdate of ammonia. The 
native variety belongs to the square prismatic system. Fign, 23, 24, 25, 
27*, 28, 33, and other forms, e : e"=76*> 40'; e : «'=128°; p '^^^^^ 40'; 
<f : r=l 28^ 20 ; j5 : a=140^ 1'. Cleavage parallel to p, t, and r. (Hauy.) 
Specific gravity=6'7e. (Mohs.) Harder than gypsum; yellow^rans- 
lucent, with a waxy lustre. Decrepitates strongly when heated and 
assumes a darker colour, which, however, disappears on cooling; fuses to 
a yellow mass. When fused upon charcoal before the blowpipe, it sinka 
into the charcoal, leaving globules of lead, while the charcoal becomes 
impregnated with molybdenum and molybdide of lead. It dissolves m 
carbonate of soda, and with that substance sinks into the charcoal, leaving 

• Jn fig. 27, read a instead of e. 



168 L£AD« 

globules. Dissolves easily in borax; the glass formed in the outer flame 
18 slightly coloured^ and that obtained in the inner flame is clear while 
hot, but in cooling suddenly becomes dark and opaque. Dissolves readily 
in microcosmic salt, forming a glass which is green if the quantity of 
mineral dissolved in it is small, but black and opaque if the quantity is 
larffer. (Berxelius.) Dissolves in heated nitric acid, with separation of 
yellowish- white nitrate of molybdic acid. It is decomposed by sulphuric 
acid. Strong hydrochloric acid dissolves it, producing a green solution, 
and forming chloride of lead, which separates more completely on the 
addition of alcohol. Soluble in caustic potash, but not in water. 

Hatchett GobeL Melling. Klaproth. Berzelius. 

Bleiberg. Bleiberg. Bleiberg. BIdberg. «art\f. 

FbO 112 .... 60-87 .... 58 .... 590 .... 61-90 .... 6442 .... 60-81 

MoO* .... 72 .... 3913 .... 38 .... 40-5 .... 40*29 .... 34*25 .... 39-19 

PbO,MoO» 184 ....10000 .... 99 .... 99*5 .... 10219 .... 98*67 .... 10000 

According to Rammelsberg, the native molybdate of lead-oxide from 
Bleiberg appears to contain a small quantity of vanadiate. The red- 
coloured molybdate from Retzbanya was declared by Johnston {Phil. 
Jdag, J, 1 2, 887) to be chromate of lead-oxide; and since, according to 
Brooke's statement, it exhibited the cirstalline form of the molybdate, 
Johnston concluded that chromate of lead-oxide must be dimorphous. 
According to G. Rose, however (Pogg. 46, 639), the red ore in question is 
molybdate of lead-oxide, with which perhaps a small quantity of chro- 
mate may be mixed. If this be the case, the dimorphism mentioned 
at page 102, vol. I, does not exist. Boussingault {Ann, Chim. Phyt. 
45, 325) examined an impure ore from Pamplona containing excess of 
lead-oxide. 

G. SuLPHOMOLTBDATB OF Lead. — Black precipitate^ remaining 
black even when dry, and producing a lead-grey streak. 

D. Persulphomoltbdatb of Lead. — ^Dark-red powder. (Berzelius.) 

Lead Ain> Vanaditm. 



Vanadiate of Lead-oxide, orLEAD-vANADiATE. — a. MonovanadiaU. 
— Formed by precipitating nitrate of lead-oxide with an alkaline mono- 
vanadiate. Also by precipitating sugar-of-lead with an alkaline bivana- 
diate, in which case acetic acid is set free in the liquid. The precipitate, 
which is yellow at first, becomes white and less bulky in the course of 24 
hours. It fuses easily, forming a reddish-yellow liquid, and on cooling 
solidifies in a yellow mass. It is decomposed by fusion with bisulphate 
of potash; not quite completely by oil of vitriol; neither is it decomposed 
by boiling with carbonate of potash. Dissolves slightly in water forming 
a yellow solution; and is easily soluble in slightly warmed nitric acid, 
even when dilute. The solution in strong nitric acid, when heated to the 
boiling point, deposits a brown powder containing oxide of lead with a 
large excess of vanadic acid. (Berzelius.) 

h. Bivanadiate. — Nitrate of lead-oxide forms with bi vanadiate of 
potash, an orange-yellow precipitate, which fuses readily, and, on cooling, 
crystallizes in a red mass. Gives up half its acid to boiling carbonate of 
potash. Slightly soluble in water, to which it imparts a yellow colour. 
(Berzelius.) 



LEAD AND CHROMIUM. 169 

Vanadite.'^Ore from Beresow. Regular sir-sided prisms. Some- 
times one part of such a prism consists of brown Yanadite and tbe other 
of Pjromorphitej a strncture whicb would seem to indicate isomorphism, 
were it not that vanadic acid and phosphoric acid do not agree in 
stoichiometric composition. Brown, with a strong lustre. Decrepitates 
strongly, and fuses on charcoal to a bead which yields metallic lead, with 
emission of sparks, and forms a yellow film on the charcoal. The solu- 
tion of the mineral in microcosmic salt yields in the outer flame a reddish- 
yellow glass, which becomes yellowish-green on cooling, — and in the 
inner flame a glass which exhibits the beautiful green of chromium. 
Dissolves easily in nitric acid, and nitrate of silver throws down a 
large quantity of chloride of silver from the solution. The ore from 
Zimapan behaves in a similar manner. (G. Rose, Fogg, 29, 455.) — Ore 
from Wanlockkead, Specific gravity 6*99. ...7*23. Colour varying from 
yellow to brown; opaque with a waxy lustre. Decrepitates when ignited 
and assumes a red colour which again becomes yellow on cooling. If 
kept in a state of fusion for a short time only, it solidifies in a yellow 
mass; but by longer fusion it is converted into a spongy, steel-grey mass, 
which, when ignited upon charcoal, immediately yields globules of lead. 
Fuses readily upon charcoal, exhaling an odour of arsenic, yields globules 
of lead, and after fusion for some time in the inner flame, likewise yields 
a steel-grey, very fusible slag, which exhibits the reactions of chromium. 
When treated with nitric acid, it first yields up the lead-oxide, so that 
the fragments become covered with a red coating of vanadic acid, which 
is afterwards likewise dissolved and imparts a yellow colour to the liquid. 
With hydrochloric or sulphuric acid it forms a green solution, chloride of 
lead or sulphate of lead-oxide being separated. (Johnston, I^. Ed. J, ofSc* 
5, 166; also Schw. 68, 119.) 



m 

FbCL.. 




139*4 


.... 

..a. 
.... 

.... 


9-78 
70-73 
19-49 


Berzelins. 
Ziiaapui. 
9*94 
.... 6800 
.... 21-34 

Z 0-72 


Of 

a... 
.... 
.... 
1... 

CuO 


Damoor. 
unknown origin. 
8*89 


9PbO 




1008*0 


63-72 


3V0» 
ZnO... 
Fe«0» 
HO ... 


3(3PbO,VO») ? 


....• 277-8 
.... 1425-2 


15-86 
6-34 
2-96 
3-80 


PbCl + 


.... 


100*00 


.... 100*00 


■••• 


101-57 



Lead and Chromium. 



Chromate op Lead-oxide, or Lead-chromate. — a. Dichromate. 
Chrome-red, — 1. Formed by boiling the pulverized monochromate with 
dilute potash-ley (Grouvelle), or with water and carbonate of lead-oxide 
(Dulong), or with | pt. l^bd-oxide and water (Badams, Ann, Phil. 25, 303; 
also Pogg, 3, 221): or by boiling it for some time with monochromate of 
potash, which is thereby converted into the bichromate. (Berzelins.) — 2. By 
boiling lead-oxide or its carbonate with an aqueous solution of mono- 
chromate of potash. (Dulong, Schw. 5, 384.) — 3. By mixing a solution of 
lead-oxide in caustic soda with chromate of potash, placing the mixture 
in a basin, and covering it with a bell-iar, under which carbonic acid gas 
is slowly evolved by Uie action of sulphuric acid on pieces of marble. 
As the soda becomes saturated with can>onic acid, the salt crjrstallizcs in 
orange-yellow needles. (Hayes.) By mixing a very dilute solution of 
nitrate of lead-oxide with chromate of potasn containing a considerable 



170 LEAD. 

i^Tiantiiy of free potadh, and exposing the mixture to the aiir, Fahiday 
{QnSiH, J, of Sc. 19, 155) obtained small red crystals, which he took for 
the monochromate, bat which, according to Wohler and Liebig, are 
really bibaaic. — 4. Bj fusing monoehroniate of lead-oxide with nitre, and 
exhausting the fused mass with water. (Hayes.) W&hler and Liebig 
{Po^. 21, 5S0) add pounded moUothromate of lead-oxide to nitre kept 
in a state of fusion at a low red heat, continuing the addition of the nitte 
in small portions at a time, till the greater part of the nitre is decomposed; 
the mixture fh>ths up and blackens, because the dichromate appears 
black when hot. The crucible is then taken out of the fire; the Btill 
fluid nitrate snd chromate of potash (which may be used in the prepara- 
tion of chrome-yellow) poured off after a few minutes; and the residue 
quickly washed with water in the crucible, because the powder becomes 
yellowish-red, if the liquid is left too long in contact with it. The salt 
thus prepared is of a pure vermilion colour; whereas, if prepared in the 
"moist way, it is more of a yellowish-red: if the nitre be too strongly 
ignited, the product is brownish. 

Small carmine-red crystals. (Dnlong.) When prepared by (4), this 
salt forms a brilliant vermilion-coloured powder consisting of delicate, 
shining crystals (Wbhler & Liebig); by (3), orange-vellow needles 
(Hayes); by (1), scarlet powder (Badams). Yields up half its amount of 
-lead-oxide to acetic acid. (Badams.) 

Badams. 

2PbO 224 .... Bi'16 8098 

CrO« 52 .... 18-84 1902 

2PbO,CrO« .... 276 .... 100-00 ~. lOO'OO 

• 

b, Senquibasic Chromate. — Melanochroite, In rhombic prisms with two 
faces enlarged, and likewise massive. Specific gravity 5*75. Very soft. 
Colour, between oochineal and hyacinth-red, with a waxy lustre; trans - 
lucent at the edges; yields a brick-red powder. Decrepitates slightly 
when heated, becoming for the time darker in colour. Fuses upon char« 
coal to a dark-coloured mass, crystalline after cbolihg. Iii the inner 
blowpipe-flame, it yields fumes of lead, lead globules, and chromic- oxide. 
(Hermann, Fogg. 28, 162.) 

Hermann. 

3?bO 336 .... 76-37 7669 

2CrO» 104 .... 23-63 2331 

3PbO,2CrO»..., 490 .... 100*00 ZZ 10000 

c. Monochromate, — Found native as Red Lead-spar, or CrocoisUe, 
Crystalline system the oblique prismatic. Form an oblique rhombic prism, 
whose obtuse lateral edge forms an angle (w:w^)=d3°44'; angle between 
the oblique terminal faces and the obtuse lateral edge (i:to)=103°15'; to- 
gether with m, t, and other faces. Cleavage parallel to «, vij and t (Hauy.) 
Specific gravity 6-1. Harder than gypsum. Colour, aurora-red; yields ah 
orange-yellow powder. Translucent, with strong refracting power and 
adamantine lustre. Decrepitates when heated, assuming for the time a 
darker colour. The salt is obtained artificially, in the form of Chrome- 
bellow, by precipitating the nitrate or acetate of lead-oxido with mono- 
chromate or bichromate of potash, — or more economically, according to 
Liebig {Mag. Pharm, 35, 258), by placing sulphate of lead-oxide, while 
still moist, in contact with a cold aqueous solution of monochromate of 
potash. White lead treated with monochromate or bichromate of potash 
likewise yields monochromate of lead-oxide and monocarbonate or bicar- 



LEAD AND CHROMIUM. 171 

fc<mfttot>f {M>tas^. (Kuhlmann, Ann. Pkarm. 41, 228.) In precipitating 
sugar- of-lead with monocfaromate of potash, the precipitate is of a paler 
colour when the liquids are cold than when they are hot, because in the 
former case it contains water. (Anthon, Repei^, 76, 129.) Bright lemon- 
yellow powder. The colour inclines more and more to red, in proportion 
as a larger quantity of dichromate is present. Acouires =a transient dark- 
red colour when heated. Fuses at a red heat, ana solidifies, on cooling, 
to a dark-browb mass which yields a bi^wnish-yellow powder; but if 
poured while still liquid into cold water, it forms an amorphous red mass^ 
and likewise yields a red powder. (Marchand.) 

Vauqueliii. PfufT. Berzelius. 

natural. natural. natural. artificial. 

PbO 112 .... 68-29 .... 63-96 .... 67-91 .... 68-38 .... 68-147 

CrO» 52 .... 31-71 .... 36-40 .... 31-72 .... 31-62 .... 31-853 

PbO,Cr(P.... 164 .... 100-00 .... 10036 .... 9963 .... 100 00 .... lOO'OOO 

When strongly ignited above its melting point, it ffives oflf about 4 
per cent, of oxygen, and is converted into a mixture of chromic oxide and 
dichromate of I^-oxide. 

4(PbO,CrO») = 2(2PbO,CrO») + Cr»0» + O. 

This mixture, if gently ignited in oxygen gas, does not re-absorb any 
oxygen. When 100 parts of chromic oxide are heated to redness in 
oxygen gas with excess of lead- oxide, 14*0 parts of oxygen are absorbed, 
and the same mixture (only with excess of lead-oxido) is therefore pro- 
duced. At a strong wnite heat, chromate of lead-oxide gives off only 
4-4 per cent, of oxygen — not nearly so much, therefore, as would be 
evolved if nothing but lead-oxide and bhroiHie oxide were to be left 
behind. (Marchand, J. pr. Chem. 1 9, 65.) The salt, when heated in a 
stream of hydrogen gas, begins to exhibit incandescence,, from formation 
of water, even before the heat is raised to redness; it likewise blackens 
and yields globules of lead; and gives off 10*7 per cent, of oxygen at a 
comparatively low temperature, and 11*8 per cent, at a higher tempe* 
raturc * 

2(PbO,CrO») + 5H = 2Pb + Ci»0» + 5H0. 

According to this calculation, 100 parts of the salt should give off 12*2 
parts of oxygen. If oxygen gas be again pasi!^ over Uie residual mass, 
and heat applied, 7 per cent, of oxygen is reabsorbed with vivid incan- 
descence. (Marchand.) — The salt when ignited with charcoal, yields 
chromic oxide and metallic lead. (Moser.) — If balls made with from 4 to 
8 parts of this salt, 1 part of sulphur, and water, be dried and then ignited 
in a glass tybe, they exhibit a dingy brownish-green colour after cooling, 
and take fire on exposure to the air, with incandescence and evolution of 
sulphurous acid; concentrated nitric acid afterwards extracts from them 
considerable quantities of chrottiic oxide alid lead-oxide; cold acetic acid 
likewiee extracts a large proportion of lead-oxide. (Anthon, Repert. 81, 
358.) The salt, when boiled with aqueous carbonate of potash, becomes first 
cinnabar-red [salt a], then yellowish-white [carbonate of lead-oxide]; and 
the liquid takes up considerable quantities of chromic acid and lead- oxide, 
which, on the addition of sulphuric acid, are completely precipitated in 
the form of chromate of lead-oxide. (Brandenburg, Scfur. N. Ann. 3, 61.) 
— The salt dissolves cempletely in caustic potash (Vauquelin); the solu- 
tion saturated while hot, deposits, after a few days, delicate yellowish-red 



172 MAD. 

laminffi of the salt a. (Wohler & Liebig.) — Heated salphnric acid decom- 
poses the salt, with fonnation of lead-sulphate; heated hydrochloric acid 
fonns a green solution of chromic hydrochlorate, with separation of chlo- 
ride of lead, and evolution of chlorine gas. If the hydrochloric acid is 
mixed with alcohol, the fonnation of the green solution is attended with 
the evolution of hydrochloric ether. The salt is insoluble both in pure 
water and in water containing sal-ammoniac; but, according to Conybearo 
(N. Edinb. PhiL J. 7, 109)| it dissolves sparingly in water containing 
phromate ef potash. 

Lbad AMD Uranium. 

Uranate of Lead-oxide. — PbO, 2U'0*. — 1. By precipitating an 
aqueous mixture of lead-nitrate and uranic nitrate with ammonia. (Arf- 
vedson, Pogg, 1, 258.) — 2. By boiling freshly precipitated lead-carbonate 
with uranic acetate till the U^rmer acquires a yellowish-red colour, and 
afterwards boiling with fresh uranic acetate. (Wertheim, «/. pr. Chem, 
29, 228.)— 3. By precipitating basic lead-acetate with uranic nitrate. 
(Persoz, Ann. Chim, Fkys. 56, 335.) — Yellowish-red substance, which 
when ignited, first becomes brown-red and then again yellowish-red. If 
heated in a pottery- furnace, it acquires a straw-yellow colour, without 
any reduction. (Wertheim.) Becomes cinnamon-coloured by ignition. 
When ignited in a cnrrent of hydrogen eas, it gives off 6*34 per cent, of 
oxygen and yields a dark brown powder [a mixture of uranous oxide and 
lead], which, if exposed to the air after perfect cooling, takes fire and is 
reconverted with incandescence, into uranate of lead-oxide (Arfvedson) : 

PbO,2U«0» + 3H = Pb + 4UO + 3HO. 
After ignition, it is very difficultly soluble in acetic acid. (Wertheim.) 

Werthdm. 

PbO 112 .... 28 28-79 

2U'0» 288 .... 72 7102 

PbO,2U«0» 400 Z 100 ~. 99-81 



Lead and Manganese. 

A. Permanganate of potash gives with nitrate of lead-oxide a brown 
precipitate, which dissolves completely in cold nitric acid, forming a brown 
solution. (Forchammer.) 

B. Manganous oxide fuses with lead-oxide, forming a green glass, 
wbich, when it takes up more oxygen from the air, assumes a brown-red 
colour. (Berthier.) 

Lead and Arsenic. 

A. Arsenide of Lead. — 1. Melted lead takes up one-sixth of its 
weight of arsenic, without visible combustion, thereby becoming brittle, 
and acquiring a laminar texture. Lead-diot are made of lead with a very 
small nuantity of arsenic — 2. Arseniate of lead-oxide reduced in a 
charcoal crucible yields a semi-ductile alloy, which exhibits a white 
fracture, and gives up all its arsenic if exposed for some time to a white 
heat in a charcoal crucible. (Fournet.) 



LEAD AND ARSENIC. 173 



B. Arsenitb of Lead-oxidb or Lead-arsbnitb. — a, Btbasie, — 
1 . By predpitating basic acetate of lead-oxide with ammonia saturated 
with arsenious acid. — White powder, which, when heated, gives off its 
combined water, and fuses to a yellowish, idio-electric, vitreous mass. (Ber- 
zelins, Ann. Chim. Phys. 11, 233.) — 2. When arsenious acid vapour is 

Ced over ignited lead-oxide, it is rapidly absorbed, the oxide fuses and 
imes red-hot, and, on cooling, solidifies to a sulphur-yellow enamel or 
glass, which fuses readily and is not decomposed, even at a bright-red 
heat. No arsenic or lead is reduced to the metallic state, unless either 
the oxide of lead or the arsenious acid is in excess; when the proper pro- 

Sortions are observed, nothing but [bibasic?] arsenite of lead-oxide is pro- 
uced. (Simon, Pogg. 40, 336.) — Arsenite of lead-oxide is not soluble 
either in aqueous ammonia, or in arsenite of ammonia or other ammo- 
niacal salts. (Wittstein.) 

Benelinf, 

2PbO 224 .... 69-35 687 

A«0» 99 .... 30-65 31-3 

2PbO,AsO> .... 323 .... 100*00 ZZ lOO'O 

(. Monobasic, — By precipitating a monobasic lead-salt with aqueous 
ammonia, which has been saturated, while warm, with arsenious acid. — 
White powder, which, when triturated in a mortar, becomes more 
strongly electrical than sulphur. When heated, it fuses to a yellowish, 
strongly idio-electric glass, and a small portion of the arsenious acid and 
combined water are given off. Slightly soluble in water. (Berzelius.) 

BeneUoB. 



PbO 

A«0» 


112 .... 5308 ..., 

99 .... 46-92 


earlier. 
.... o4*o<53 
.... 45-667 


■ ••• 
•••• 


later: 
52-644 
47-356 



Pb0,A«O* 211 .... 100-00 100-000 .... 100000 



C. Arseniate of Lbad-oxidb or Lead-arseniate. — a. Terhasie.-^ 
1. By precipitating neutral lead-acetate with diarseniate of soda, in 
whicn case free acetic acid remains in the liquid, or by precipitating any 
lead-salt with diarseniatQ of soda in excess, whereby monoarseniate of 
soda is produced. (Mitscherlich.) — When neutral lead-acetate is precipi- 
tated by trisarseniate of soda, the precipitate contains more than 3 atoms 
of base if the lead-salt is in excess; but if a solution of i part of lead-acetate 
be added to a solution of 1 part of trisarseniate of soda (in which case 
the latter will predominate), the precipitate will consist of terbasic salt. 
(Graham, Pogg. 32, 51.) — 2. By digesting b with ammonia. (Berzelius.) 
white, fusible powder. (Berzelius.) When raised to a low red heat, at 
which it neither fuses nor bakes together, it acquires a transient yellow 
colour. (Graham.) Insoluble in water; likewise insoluble in aqueous 
ammonia and its salts. (Wittstein.) 

BenEeliuB (2). Graham (1). 

3PbO 336 .... 74-5 74-75 74*33 

AaO* 115 .... 25-5 25-25 25-67 

3PbO,AaO* 451 .... 100-0 ZZ 10000 ZZ 10000 

b. Bibasic. — Formed slowly by the action of air and aqueous arsenic 
acid upon lead; precipitated on mixing aqueous bydrochlorate or nitrate 
of lead-oxide with arsenic acid, — or on gnidually dropping diarseniate of 
ammonia, potash^ or soda^ into an excess of mononitrate of lead-oxide. 



1Y4 LEAD. 

(BerxeliuBy MiUcherlich.) FuBes more easily than a, ibnning an opaqne 
maw; crystallizes on cooling, according to Alitacherlich, bi^t according to 
H. Rose it does not. On charcoal in the inner flame, it exhales an odour 
of arsenic, and yields globules of lead. (H. Rose.) Dissolves in hydro- 
chloric or nitric acidj but not in water or acetic acid. 



2PbO 

AsO* 

HO 


224 .... 66Q8 
115 .... 33-92 

• ••■ 


.... 65-86 
.... 3414 


Th^nard. 

.... 64-3 
.... 35-7 

• •■V 


CheneTix. 
63 

.... M<3 


2PbO,A80» 


339 .... 100-00 


.... 100-00 


.... 1000 


.... 100 



D. SuLPHARflENiTS OF Lba|)« — 2PbS, AsS^. — Red-brown precipitatCj 
black after drying, and yielding a brown powder j fuses readily without 
giving ofl* sulphide of arsenic, and solidifies to a metal-grey mass, having a 
shining, crystalline fracture, and yielding a ffrey powder. (Berxelius, Fogg, 
7, 147.) — 10 parts of galena heated to whiteness in a charcoal crucible 
with 5 parts of orpiment, volatilize, leaving only 1 part of ductile lead; 
hence orpiment favours the volatilization of sulphide of lead. (Foumet.) 

E. SuLPBARSENiATE OF Lead. — Lead-salts give dark brown precipi- 
tates with the aqueous solution of bibasio snlpharseniate of sodium, and 
red with the terbasic salt. Both precipitates turn black when dry. (Ber- 
zelius.) 

F. Arseniate op Lead-oxibe with Chloride op Lead.— In many 
kinds of Pyromorpkite (p. 149), especially in the yellow variety, the 
phosphoric acid is partly replaced by arsenic acid. Specific gravity 
7*208. (Mohs.) The ore which contains arsenic acid Is distinguished 
from that which contains phosphoric acid only, by the arsenical odour 
which it evolves when heated on charcoal before the blowpipe, and by 
being rapidly reduced to metallic lead alloyed with arsenic 

G. Arsenide op Lead and Potassium. — Formed by igniting in a 
well closed crucible, 2 parts of lead, 1 of arscnious acid, and 2 of tartar. 
The mass when immersed in water by itself remains almost unaltered, — 
but if in contact with mercury, which removes the coating of lead, it 
yields, in the course of a few weeks, a large quantity of arseniuretted 
hydrogen gas. (Serullus, J". Phys. 93, 137.) 



Lead and Antimony. 



A. Antimonidb op Lead. — a, Pb^^Sb. — Found on the hearth of 
a smelting-fumace at the Mulder works. Broad, thin, six-sided prisms, 
with two of the lateral faces very much enlarged, and the angles of the 
lateral edges, about 144°, 97°, and 133°. Specific gravity 9-21. Mal- 
leable; of the hardness of calcspar; steel-grey. Fuses less easily than 
pure lead, and covers the charcoal, first with a white film of lead-oxide, 
then with a similar film of zinc-oxide, and lastly with a yellow film of 
lead-oxide. (Karsten, Pogg, 55, 118.) 



LEAD AND ANTIMONY. 175. 

Kalsten. 

18Pb 1872 .... 93-55 . 90-10 

Sb 129 .... 6-45 6-48 

Zn .... 1-42 

Ca .... 1-50 

Ag .... 0-24 

Ni,AB,S .... trace 

PbW,Sb 2001 .... 10000 iZZ 9974 

h. PVSb. — An alloy of 416 parts lead, and 129 antimony is laminar, 
brittle, blaish-white, shining, and does not evolve antimony when heated 
tb whiteness in a charcoal crucible. (Foumet.) — c. Pb^Sb. — ^208 pt«. lead 
with 1 29 antimony give off but a small quantity of antimony when heated 
to whiteness in a charcoal crucible. — With 2 At. antimony a larger 
quantity is evolved, and with 6 atoms, a very large quantity. (Foumet.) 

Type-metal contains 83 pts. lead and 17 antimony. (Heeren.) An 
alloy of 3 pts. Tead and 1 pt. antimony is ductile but hard; that which 
contains equal portions of the two metals is brittle and laminar. 

B. Antimoniatb op Lead-oxide. — Prepared with nitrate of lead- 
oxide and antimoniate of potash. Formed likewise by treating antimonido 
of lead with hot nitric acid. — White curdy precipitate; turns yellow and 
gives off water when heated; infusible. Wnen ignited on charcoal before 
the blowpipe, it is reduced, with slight detonation, to antimonide of 
lead. Not completely decomposed by nitric acid. Insoluble in water. 
(Berzelius.) 

Naples Yellow is antimoniate of lead-oxide. It is formed by mixing 
intimately I part of tartar-emetic, perfectly freed from iron by re-crystal- 
lization, with 2 parts of crystallized lead-nitrate and 4 parts of common 
salt—igniting the mixture in a hessian crucible for two hours, at a heat 
sufficient to fuse it — separating the cooled mass from the crucible by 
slight blows — and extracting the chloride of sodium with water. By 
this treatment, the Naples Yellow is disintegrated and reduced to a fine 
powder; if too strong a heat has been applied, it forms a hard mass which 
will not disintegrate. — A cheaper but less beautiful product is obtained 
by mixing 2 parts of a pulverized alloy of equal parts of lead and antimony 
(or pulverized printing types) with 3 parts of nitre and 6 of common 
salt, then heating to redness and exhausting with water as above. 
(Brunner, Pog^f. 44, 137; also J. pr, Ghem. 10, 196.) — Older recipes: 
12 pts. white lead, 3 antimonium diaphareticum, 1 sal-ammoniac, 1 alum 
or pearl-ash; or: 16 grey sulphide of antimony, 24 lead, I common salt, 
1 sal-ammoniac, &c. The mixture is to be ignited in the air gently at 
first, but afterwards more strongly for several hours, and then washea. — 
Orange-yellow, very permanent oil-colour. 

C. SuLPHANTiMONiTE OP Lead. — Lead-grey with metallic lustre, 
easily fusible; when ignited upon charcoal, it evolves sulphurous acid 
and forms a white and afterwards a yellow deposit. According to 
Fournet, it leaves antimonide of lead when ignited in the charcoal 
crucible. Hot nitric acid converts it into a white powder of antimoniate 
of lead-oxide. Dissolves in strong boiling hydrochloric acid with 
evolution of sulphuretted hydrogen. — a. SexwmCn — KiMrickenUe,^^ 
Sp. gr. 6*407. (Apjohn, Jakreaber, 22^ 193.) 



178 LEAD. 

Ill the outer flame tlie metallic deposit is smaller, the yellowish-brown 
more considerable. When the mineral is fused in an open glass tube, a 
rinj^ of white drops forms round it, and the white fume which rises, yields 
a white sublimate, which runs together into a drop when heated (telluric 
oxide). Dissolves in cold nitric acid, but more quickly iu the same acid 
when hot. (G. Rose, Fogg. 18, 68.) 

G. Rose. 

From Altai. 

Pb 104 .... 61'9 60-35 

Te 64 .... 38-1 38*37 

Ag .... 1-28 

PbTe iei Z, 1000 ZZ loooo 

B. Tellurite op Lead-oxide. — a. Basic. — Tellurite of potash 
yields with basic lead-acetate a bulky, translucent, somewhat soluble 
precipitate.— 6. Mojiotellurite. — By precipitatiou of neutral lead-acetate. 
The white precipitate, when heated, gives off water, turns yellow, and 
then fuses into a translucent mass. Before the blowpipe, on charcoal, 
it is reduced, with slight detonation, td telluride of lead. It is easily 
soluble in acids. (Berzelius.) 

Berzdius. 

PbO 112 .... 58-33 57-8 

TeOa 80 .... 41-67 42-2 

PbO,TeO« 192 .... 100-00 ZZ 1000 

C. TELLtTRATE OF Lead-oxide.^o. Basic. — Monotellurato of potash 
gives with basic lead-acetate a white, voluminous precipitate, difficult to 
wash, and not quite insoluble in water. — h. MonoteUurate. — The preci- 
pitate formed with neutral lead-acetate is white, heavy, and somewhat 
soluble in water. — c. Bitellurate. — By precipitating neutral lead-acetate 
with bitellurate of potash or soda. The precipitate is more soluble in 
water than h, — d. QiuidroUllui'ate. — The precipitate obtained with au 
alkaline quad rotellu rate turns yellow when ignited, and white again on 
cooling. It dissolves in dilute nitric acid, even after ignition; more 
sparing in dilute acetic acid, remaining in the form of a white powder 
when tbe acid evaporates; it is soluble to a considerable extent in water. 
(Berzelius.) 

D. SuLPHoTELLuniTE OP Lead. — The brown precipitate turns black 
on drying, gives off water when ignited in a retort, and lef^ves a grey 
majss having the metallic lustre. (Berzelius.) 



Lead and Bismuth. 

A. AlloIt op Lead and BrsMUTtt.— These metals unite readily in all 
proportions and with condensation. When 3 At. lead are united with 
2 At bismuth, the mixture exhibits but one solidifying point (p. 103), 
viz at 129'; when the metals are united in other proportions, a higher 
solidifying point likewise exists besides the former, viz. at 146"^ in Pb*Bi, 
and at i\V in PbBi. (Rudberg.) a. When alloyed with a small quantity 
of bismuth, leaH retains its malleability, but becomes much more tough.— 
h. Pb'Bi = 312 : 2 13. Puses between 163' and 171^ (Dobereiner, 
Schw. 42, 182.) — c. 1 part of lead to 1 part of bismuth: Brittle, with 
laminar fracture, the colour of bismuth, and specific gravity 1 0*7097. 



LEAD AND TIN. If 9 

(Mnschenbroek.) Ligbt lead-grey; dose-gmined; does not expand in 
cooling. (Marx.) — d, 1 part of lead to 2 bismath: Fracture crystalline 
and coarse-grained; does not expand perceptibly in solidifying. (Marx.) 
— e. 1 part lead to 3 bismuth: Fracture laminar; expands slightly in 
solidifying. (Marx.)— ^. 1 part lead to 8 bismuth: Coarsely laminar; of 
the colour of antimony; expands in solidifying. (Marx, Schw, 58, 463.) 
— IT According to Thomson, the alloy PbBi has a specific gravity of 
10-831, and melts at 134 S''; and PbBi' has a sp. gr. of 10*509, and melts 
at 128-2^ (Liebig and Kopp's Jahresber, 1849, 1040.)— Bi'Pb* fuses 
at 122-4°. (Person.) IT 

B. SuLPHOBiSMUTHATE OF Lead. — dPbSjBiS*. — KobdlUs. — Specific 
gravity 6-29. ..6-32. Fracture radiating. Colour dark lead-grejr with 
metallic lustre, like crude sulphide of antimony; not very hard; yields a 
black powder. When ignited in an open tube, it yields sulphurous acid 
and antimonic oxide; fuses with strong intumescence at first, but after- 
wards quietly, and becomes surrounded with a yellow glass. Forms a 
white deposit on the charcoal in a weak blowpipe flame, and a yellow 
deposit in a stronger flame. In the inner flame it fumes strongly and 
yields a white metallic bead. With carbonate of soda it melts together 
and sinks into the charcoal^ leaving a semi-malleable metallic globule. 
(Setterberg, Pc^y. 55, 635.) 











Setterberg. 










From Nerike. 


3PbS 


360 


>••• 


57-97 


46-36 


BiS» 


261 


•..* 


4203 


83-18 


FeS ^. 




• x. 




...... 4*72 


Cu»S 




I... 




108 


SbSa 




.... 




12-70 


Matrix 




• •«• 




1-45 


3PbS,Bia> 


621 


.••« 


10000 


99-49 



In this mineral, FeS probably replaces part of the PbS, and SbS' part of 
the BiS'. 

Lead amp Zinq. 

Allot of Lead and Zma — Lead readily unites with rino, thereby 
becoming harder; but its ductility is pot impaired by any proportion of 
jsiuc. (J. F. Gmelin.) When it is heated tQ whiteness in u, ch^coal 
crucible with ^..,.\ fino, the lead givei np tb^ whple of the zine» 
(Foumet.) 

tSAD AND T^« 

A. ALLOTe OF Lead and TiN.-^Lead and tin unite w all ^opoHioiic. 
The alloy is harder, more tenacious and more fusible than Mtjber tin or 
lead alone. From an alloy containing not more than d P^^ ^ 1^ to 
1 part of tin, vinegar dissolves out nothing but the tin. (Proust, Gummi^ 
Pfaff, Ann. Ohim. 57, 13; Schw. 6, 225; 11, 14.) 

The specific gravity of the alloy is below the mean deiermiaed by 
calculation; 2 volumes of tin combine with 1 volume of lead, almost 
without change of volume (denoted in the table by 2 :1M.); ^^ ^^^ 
farther the proportions deviate either way irom tUa atandard; the 

n2 



18* 



LEAD. 



greater is the difference between tbe calculated and tbe actual density, as 
shown by the following table. In this table the melting points (M.P.) of 
the alloys are also given. — The specific gravities and melting points of 
some of the alloys, as determined by Thomson, are likewise added. 



KnpflTer. 



.ii^>». 



Specific gnntj. 
observed, calculated, diff. 



Sn«Pb 

8n*Pb 

8n*Pb 

Sa>Pb 

2: IM 

Sn'Pb 

SnPb 

SnPbS 

SnPb< 

SnPb« 



7-9210 .... 7-9326 



8-0279 

81730 

8-3914 

8-6371 

8-7454 

9-4263 

10-0782 

10-3868 

11-5551 



8-0372 

81826 

8-3983 

8-6:^75 

8-7518 

9-4366 

10-0936 

10-4122 

10-6002 



116 

93 

96 

69 

4 

64 

103 

154 

254 

431 



M.P. 



194 
189 
186 
194 
196 
241 

239 



Thomson. 



Specific gravity, 
obs. cal. 



M.P. 



diff. 



7-850 .... 8-545 .... 695 .... 1900' 

8-549 .... 9-002 .... 453 .... 1828 

8-688 .... 9-209 .... 521 .... 182-8 

9-288 .... 9-899 .... 611 .... 182-2 



Regnault (Ann. Chim. Pht/s. 76, 136) found the specific gravity of 
Sn«Pb=8-777, and that of SnPb=9-387 at 13-3°. 

The alloy Sn'Pb has one solidifying point, viz. at 187° (182-g accord- 
ing to Person); the other alloys likewise exhibit a higher solidifying 
point, which for Sn^*Pb, is at 210°;— for Sn«Pb, at 200^^;— for Sn*Pb, at 
190;— for Sn'Pb, at 200^;— for SnPb, at 240°;— for SnPb*, at 270;— and 
for SnPb», at 280. (Rudberg.) 

32 parts of tin to 1 lead : ( Vierstempliges Zinn). — 5 parts of tin to 
1 lead (Dretstempliges Zinn). The ordinary proportion fixed by law 
for tin- vessels. — 4 parts tin to 1 lead; Five-pound Tin {Fiinfpfundiges 
Zinn). — 3 parts tin to 1 lead; Four-pound Tin {Vierpfundiges Zinn). 
— 2 parts tin to 1 lead : Fine solder; Three-pound Tin (Zweistempliges 
or drexpfilndiges Zinn), — 1 part tin to 1 lead: Common solder; Tifo- 
pound Tin {Zweipfundiges Zinn). — 1 part tin to 2 lead : Coarse solder, ' 

B. Stagnate of Lead-oxide. — An alloy of lead and tin fused in 
contact -with the air oxidizes much more quickly than either metal alone, 
the change being accelerated by the afllnity which the two oxides have 
for one another. The alloy of 1 part tin with 4 or 5 of lead burns at a 
red heat like charcoal, the combustion afterwards going on spontaneously 
like that of inferior peat, with formation of cauliflower-like excrescences. 
(Berzelius.) The presence of platinum in the alloy, retards the combus- 
tion; gold, on the contrary, does not interfere with it, being apparently 
converted at the same time into purple oxide. (Fox, J. Roy, Inst. 1, 626.) 
— Aqueous stannate of potash mixed with, a lead-salt gives but a slight 
precipitate of stannate of lead-oxide: it appears to be somewhat soluble. 
(Moberg.) — The lead-ash containing tin, or tin-ash containing lead, 
obtained by oxidating an alloy of the two metals, forms a white opaque 
Enamel when fused either alone or with silica and alkali : Dial-plates and 
other White Enamels, 

C. Antimonide op Lead and Tin. — Antimonide of tin is ^ndered 
brittle by admixture of lead. (Chandet.) 

D. Allots op Bmmuth, Lead, and Tin. — 2 parts of bismuth, 1 lead 
and 1 tin, form Rose's Fusible metal; 8 parts bismuth, 5 lead and 3 tin; 



OTHER COMPOUNDS OF LBAD. 181 

Newton's and d*Arcet*s; 5 parts bismnth, 2 lead and 3 tin: Lichtenberg's. 
All these alloys melt below the boiling point of water. An alloy of 
426 parts (2 At.) bismntb, 177 (3 At.) tin, and 312 (3 At.) lead, fases, 
according to Dobereiner, at 99°. — Rose's fusible metal melts at 93 75°. 
(G. A. Erman, Fopff. 20,283.) — In whatever proportion the three metals 
are mixed, they exhibit one fixed solidifying point, at 98^, and two higher 
ones which are variable. (Rudberg.) — Rose's fusible alloy does not 
expand in solidifying; hence a glass tube into which the melted alloy 
is drawn up, cracks lengthwise, when nearly cold. (Marx, Schw. 58, 
468.) 

Sn^Pb'Bi has a density of 1M94 at ll^ and fuses at 120°; Su*PbBi 
has a density of 9*253 at 20°, and fuses at 95^ (Regnault, iV. Ann. Chim. 
Phys. 1, 137.) Sn»Pb*Bi» fuses at 96°; Sn*PbBi at 145^ (Person, 
Jahreiber, L, & £. 1850, 72.) 

120 pounds of an alloy of 3 pts. tin, 2 lead, and 5 bismuth, yielded, 
on cooling, tolerably definite crystals which fused below 100^, and con- 
tained, Sn 15*76, — rh 26*56, — Bi 57*68, or equal numbers of atoms of 
the three metals. (Lobell, J, pr. Chem. 26, 511.) 

Potassium added to fusible metal raises its melting point. (H. Davy.) 

E. Alloys op Lead, Tin and Zinc. — The alloy ZuSn'Pb' = 
ZnSn',2]'bSn' exhibits but one solidifying point, viz. at 168°; all other 
alloys of these three metals have likewise two higher solidifying points, 
h andc. (A. & L. Svanberg, Fo^ff. 26, 280.) 

Atoms. Atoms. 



Zn 


Sn 


Pb 




a. 


b. 


c. 


Zn 


Sn 


Pb 


a. 


b. 


c. 


3 


11 


2 




168 




182 


1 


12 


3 


••.. 168 


172 




1 


6 


1 




168 


171 


204 


1 


18 


4 


.... 168 


172 


178 


1 


9 


1 




168 


178 


183 


■.... A 


21 


6 


.... 168 




175 


1 


9 


2 




168 




.•• 


••**• X 


33 


10 


.... 168 




178 


1 


12 


2 




168 




178 















Other Compounds of Lead. 

With Iron, Nickel, Copper, Mercury, Silver, Gold, Platinumi Palla- 
dium, Rhodium and Iridium. 



182 



Chaptsr XXXII. 



IRON. 



Bergman. De analysi Ferii. Opusc, S, 1. 

Th^nard. Oxides of Iron. Ann, Chim. 56, 50; also iT. GM. S, 648. 

Bncholz. Oxides of Iron. N. Gehl. 3, 696. 

Gay-Lnssao. Oxides of Iron. Ann, Chim. 60> 163; also &U^, 42, 265. 

Further: Ann. Chim. Phys, 1, 33. 
Berzelins. Compounds of Iron with Snlphur and Oxygen. Gilh. 87, 

296; 42, 277. Further: Ann, Chim. Phys. 5, 149; also N. Tr. 2, 

2, 359. — Pogg. 7, 393. — Atomic weight of Iron. Ann.'Pharm. 50, 

432. 
ftinmann. History of Iron and its applicatioii in the arts and manttfac- 

tures; translated into German by Georgi. Berl. 1785. 
Karsten. HandJbuch der £tsenhnttenkM%de, Halle, 1816. — System der 

MetaUurgie. 1831—32. B. 4. 



SiTNONYMES. Eisen, Fer, Ferrum, Mars. 

History. Knives and arms of iron are mentioned in the books of 
Moses. The ancient Greeks, on account of the difficulty of manufactur- 
ing iron, generally used arms made of an alloy of copper and tin. — The 
chemical relations of iron haye been investi^ted chiefly by Bergman, 
Proust, Bucholz, Gay-Lussac and Berzelius. Ferric acid was discoyered 
by Fremy. 

Sources. The most widely diiSused of all the heavy metals. It 
occurs native, though rarely, sometimes in meteoric masses, sometimes in 
fine granules in Mica-slate (Kastn. Arch. 11, 364), sometimes in Cerite 
{Ann.Pharm.il, 245); as protoxide; as sesquioxide; as hydrated 
sesquioxide; as carbonate, phosphate, sulphate, hydrochlorate, silicate, 
titanate, tantalate, niobiate, pelopiate, tungstate, arseniate, and oxalate of 
the protoxide or sesquioxide; as protoxide combined with alumina or 
sesquioxide of chromium; as eight-sevenths sulphide of iron; as bisulphide; 
as sulphide of iron combined with other metallic sulphides, in Copper 
pyrites, Peacock copper. Grey copper. Arsenical pyrites, and Sternbergite; 
and finally, in small quantity, often as a colouring principle of various tints, 
in a great number of mineral substances; and in most organic bodies. 

Preparation on Hie large scale. — Principally from ores containing the 
protoxide or sesquioxide. The ores are commonly roasted in the first in- 
stance to free them from sulphur, arsenic, &c., then coarsely pounded, mixed 
with charcoal or coke^ and a flux to fEbcilltate the fusion of the earthy 



lAON. 183 

matters contained in the ore, and exposed to the ihost intense white heat in 
tall smelting furnaces (Hoheisendfen) urged by a strong blast. If the ore 
contains alumina and silica, lime is nsed as a flux; a caKareous ore, on 
the contrary, requires the addition of minerals containing silica and 
alumina: the best mode of proceeding is to mix calcareous with tiliceous 
iron-ores, so that each may act as a ftux to the other. — The iron reduced 
from the melting mass — Fig-iron, Cast-iron — which is freed from time to 
time from the slag which floats on its surface, and run off at the bottom, 
or scooped ont several times in a day — is contaminated with various 
matters which will be mentioned under the head of Cast-iron: from these 
it is freed on the large scale by a partial oxidation, called the Refining 
process {das Exsenfrischen oder Frischprocess), whereby chiefly the foreign 
substances are oxidized, and separated partly as gas, partly in the form 
of a slag, called Cinder (^FrUchschlacJce), whilst a purer and malleable 
iron remains, called Bffined iron, liar iron, or Wrought iron {Finsckeisen, 
Staheisen, ISchmiedei^en), The carbon which is oxidized, partly by the 
air, and partly by the cinder produced in the process, escapes in the form 
of carbonic oxide; the cinder consists of silicate of lime, magnesia, alu- 
mina, nianganous oxide, ferrous oxide, &c. In proportion as the iron 
becomes purer, it loses its liquid form and becomes granular: as the purifi- 
cation advances, it welds together, and is then perfectly purified and formed 
into bars either under the hammer dr between rollers. This oxidation 
takes place either by fusion with charcoal while a blast of air is blown 
upon the mass : Refining upon hearths {Fii^hharkeit auf Heerdtn), or 
by contact with the flame of coal in reverberatory furnaces : Puddling. 

Bar-iron still retains about ^ per cent, of carbon, which makes it 
harder; generally also it contains a small quantity of silicium; sometimes 
phosphorus, which makes it brittle when cold; — or sulphur, arsenic, 
tjopper, which make it brittle at a red heat, — ^and other metals. 

Purification, — 1. By melting iron filings with one-fourth their weight 
of smithy scales under a layer of green glass, — or of glass prepared for 
the purpose and free from heavy metals — the whole being enclosed in a 
crucible with the cover luted down, and the fire urged by a strong blast. 

SBroling.) By reducing a pure oxide of iron with hydrogen gas. 
Berzelios.) 

Properties, Iron sometimes exhibits cleavage parallel to the faces of 
a cube. This was observed by Wbhler {Pogg. 26, 182) in iron-plates 
which had been imbedded beneath the hearth of an iron-smelting 
furnace and exposed to a strong white heat during the whole time of 
smelting. The same appearance was noticed by Breithaupt {J. pr, Chem, 
4, 245) in the Aachner meteoric iron. Wbhler likewise found iron 
crystallized in octohedrons in the hollows of a large cast-iron roller. — 
Wrought iron has a fibrous texture. It is the hardest and toughest of 
all the ductile metals; it cannot be beaten out into very thin plates, but 
may be drawn out into very fine wire. Iron purified (1) by fusion with 
smithy-scales has, after solidification, a density of 7' 8439, which is 
rather increased than diminished by rolling ont into plates or drawing 
into wires. (Broling.) The purest soft bar-iron, containing but a trace 
of carbon, has a density of 779 (Karsten); that of ordinary bar-iron is 
7*788. (Brisson.) — At a red heat, iron becomes softer and tougher; at a 
white heat, it may be welded; at a temperature above the welding point, 
it crumbles under the hammer; its melting point approaches the limits 



184 IRON. 

of temperature tliat can be obtained by ordinary means, — ^being, accord- 
ing to Pouillet, at 1550° C, according to Daniell, at 1587^ according to 
Morreau, at 6346^ C. or 175° Wedg., and according to Mackenzie, at 
158° Wedg. At a still higher temperature, such as that produced bj 
Hare*8 deflagrator, or by the combustion of iron in oxygen gas, it vola^ 
tilizes. If an electric current be passed by means of charcoal points 
through iron placed in yacu<>, there is formed a quantity of yapour of 
iron, which bums with a flash on afimitting the air, and deposits a 
yellowish-red film upon the glass. (Hare.) — Iron is attracted by the 
magnet, and may itself be rendered magnetic, but loses this property 
the more quickly in proportion as it is free from carbon. Iron reduced 
from the oxide by hydrogen is a grey powder (Berzelius); in this state it 
does not conduct electricity. (Higgins & Draper, y, Edinb. FhU. «7. 14, 
315.) 

Atomic weight of Iron^21'\2n (Berzelius) =25 '68 (Capitaine, Ann. 
Chiin.Fkps.77, 126.) — H According to a more recent determination of Ber- 
zelius (Ann. Pharm. 50, 482), the true atomic weight of iron is 28. The 
errors m preyious determinations appear to have arisen from the neglect 
of making due allowance for the impurities contained in the iron. IT 



Com2>ounds of Iron. 
Ibon and Oxtgsn. 

1. Iron when in solid masses remains unchanged in the air at ordi- 
nary temperatures; the finely divided iron obtained by decomposing the 
sesquioxiJe by hydrogen gas at as low a temperature as possible — if 
allowed to cool perfectly in the atmosphere of hydrogen and then exposed 
to the air — instantly takes fire and is converted into sesquioxide. 
(Magnus, Pogg. 3, 81; 6, 509; comp. II. 27; and Stromeyer, Pogg. 6, 
471.) Iron reduced by hydrogen at a red heat, does not take fire till 
heated nearly to redness. 

2. Coherent iron heated to redness in the air oxidizes without vi^sible 
combustion, and forms ferroso-ferric oxide: Scale-oxide of Iron, Smithg^ 
scales — which, by prolonged ignition, is converted into ferric oxide (ses- 
quioxide). The successive shades of yellow, red, blue, and lastly grey, 
with which polished iron becomes covered during the operation of tem- 
pering, are due to the very thin films of ferroso-ferric oxide, which 
transmit light more or less, producing the tints of Newton's coloured 
rings. 

8. Iron heated to whiteness in the air or in oxygen gas bums with 
vivid sparkling, and forms ferroso-ferric oxide; in common air, the com- 
bustion soon ceases; but in oxygen ^^as it continues, if the piece of iron be 
tbiit {comp. II. f34); and tbe high temperature thereby produced, causes 
the volatilization of part of the iron, which is then converted into sesqui- 
oxide. A bar of iron heated till it emits sf arks (t. e. to the welding 
point) will burn even in the air, if the blast of the bellows be strongly 
directed upon it, or if it be swung rapidly round. (Addams, Phil. Mag. J. 
11, 407, and 446; also J. pr. Chem. 12, 317; Boerley, Stratingh, N. Br. 
Arch. 22, 305; Darcet, Pogg, 31, 496.) In the collision of flint and 
eteel, fine particles of steel are detached by rubbing on the stone, and 
brought to such a temperature that they take fire in the air, and impart 
their combustion to tinder. Henoe, according to H. Davy {Gilb, 1 7, 446), 



XROX* 185 

ft flint and steel in vacno gives but very faint sparks, proceeding from 
ignited particles of stone; and, according to the same authority, iron in 
very fine particles takes fire much below a red heat. 

4. Iron when covered with a thin layer of water and exposed to the 
air, is converted into hydrated sesquioxide, by taking up the oxygen 
which the water absorbs from the air, and combining as oxide with a 
portion of the water, in this reaction, there is likewise produced a portion 
of ammonia, which partly escapes and partly remains in combination 
with the hydrated ferric oxide; — the formation of the ammonia is due to 
the decomposition of a portion of the water, and to the combination of its 
hydrogen with the nitrogen of the air which has been absorbed by the 
water. (11.418, 419.) If the iron be covered by a deeper stratum of 
water in a vessel exposed to the air, so that the transference of the oxygen 
of the air through the water to the iron may take place more slowly, a 
formation of black hydrated ferroso-ferric oxide takes place, because 
hydrated ferric oxide, as it slowly forms, induces the iron to decompose 
t^te water, and form ferrous oxide, with which the ferric oxide then unites. 
(Wbhler.)— Iron remains unaltered in damp air, provided no water is 
deposited upon it — as, for example, under a bell -jar, closed at bottom with 
a water-joint, and having a piece of tarnished lead likewise placed under 
it, the water being then deposited exclusively upon the lead. But if 
there are cracks in the iron, and these cracks are filled with scale-oxide, 
water becomes deposited upon this oxide, and rusting then takes place. 
Iron also rusts quickly in damp air containing small quantities of sulpha* 
retted hydrogen (which first forms sulphide of iron and then ferrous 
sulphate), chlorine, hydrochloric acid, and acetic acid; but carbonic acid 
and ammonia have no influence. (Bonsdorff, Poffff. 42, 332.) — Iron does not 
mst in the air nnder water containing small quantities of alkaline sub- 
stances. When immersed in aqueous ammonia, potash, or soda, it remains 
bright for months. If water at 22° be saturated with hydrate of potash, 
one measure of this solution is sufficient to impart this preservative power 
to 2000 measures of water; but if the mixture contains from 4000 to 
5000 measures of water, iron rusts when immersed in it; it likewise rusts 
in a mixture containing from 1000 to 2000 measures of water, if the 
liquid be completely saturated with carbonic acid. One measure of a 
saturated solution of carbonate of soda may be diluted with .54 measures 
of water without causing iron to rust; but if the quantity of water be 
increased to .50 measures, iron rusts when immersed in it. One measure 
of a saturated solution of borax may be diluted with 6 measures of water, 
and one measure of lime-water with three measures of water, without 
losing its preserving power; but if the proportion of water be increased 
in either case, rusting ensues. The preserving influence of alkalis does 
not, in all probability, arise from their power of withdrawing carbonic 
acid from the water; for iron rusts even under thoroughly boiled water, 
in contact with air free from carbonic acid ; it is true that the mixture of 
aerated water with potash has the efleot of expelling the air; but if the 
water 1^ in great excess, the expulsion is veiy imperfect : moreover, car- 
bonate of soda drives out but a small quantity of air, and borax none; 
and yet these substances prevent oxidation. (Payen, Ann. Ckim, Phys, 
50, 305.) — Wetzlar {Schw. 49, 484) showed, long before Payen, that iron 
does not rust in aqueons solution of potash or ammonia, even though the 
solution may be diluted, and that in saturated solutions of sulphate or 
nitrate of potash, it oxidates more slowly than in pure water, inasmuch 
as, according to his obeervationsy these liqnids contain less air in eolation. 



186 IRON, 

HaH (iV^. Quart. J. of 8c. S, 262; also Po^. 14, 145) likewise foiind that 
iron does not rnst nnder water into which lime or magnesia has been 
thrown, or even in a mixture of 1 part of lime-Water with 4 parts of 
water. — Iron rusts more slowly in proportion as its surface is smoother; 
the rust is formed most abundantly in cracks. The purest iron rusts the 
most quickly; hard wrought iron, richer in carbon, rusts more slowly; 
then follows soft steel, then hard steel, then soft cast-iron, and lastly hard 
cast-iron. The presence of sulphur in iron accelerates the rusting; phos- 
phorus appears to retard it. Beneath the ilocculent hydrated sesqui- 
oxide, there is formed a thita black crust [of ferroso-ferric oxide 1] which 
adheres firmly to the iron. Contact with cine protects the iron from rust- 
ing only so long as the zino does not itself become covered with a film of 
oxide. Tin in contact with iron accelerates the rusting. (Mor. Meyer, 
J. techn. Chem. 10, 833.) — A water-conduit consisting of cast-iron pipes 
became stopped up in the course of a few years by the formation of 
tuberculous masses of hydrated ferric oxide. Accordmg to Pay en, grey 
cast-iron oxidates more readily than white, and even than bar-iron; in 
iron pipes, grey and white cast-iron are mixed: now, if the water contains 
too little alkali to protect the iron completely, the parts consisting of 
grey iron become oxidated and produce the formations of rust. When 
cast-iron of this description is exposed to the action of a mixture of 75 
measures of aerated water, and one measure of a saturated solution of 
common salt and carbonate of soda^ oxidation begins in a minute, and 
there is formed, — first, whitish hydrated ferrous oxide and hydrated 
ferroso-ferric oxide, which at some distance from the iron, are converted 
into hydrated ferric oxide, — and afterwards carbonate and silicate of 
ferrous oxide, the latter being produced by the oxidation of silicide of 
iron. In water containing nothing but common salt, protochloride of 
iron is likewise formed. In water containing 0*2 per cent, of soda- 
hydrate and 0*6 of common salt, the oxidation is confined within smaller 
spaces around the points at which it originates, and spreads in vermicular 
forms. At the oxidized points, the iron becomes richer in graphite, and 
at the same time blacker and softer. (Payen, Ann. Ohim. Phys. 63, 405.) 
Since this rapid rusting seldom takes place in cast-iron water-pipes, it is 
probable that a peculiar composition of the east-iron is necessary to its 
occurrence. (Gm.) 

5. Red-hot iron in contact with aqueous vapour liberates hydrogen, 
and is converted into ferroso-ferric oxide FeO,FeO', in small octohedrons. 
(Gay-Lussac, Despretz, Ann. Chim. Phys. 62, 346.) According to 
Haldat {Ann.Ckim. Phys. 46, 70), rhombohedrons of ferric oxide are 
formed, similar to those of specular iron; but they were not analyzed. — 
According to Stromeyer {Pogg. 9, 475), the iron takes up variable quan- 
tities of oxygen, the amount being greater as the temperature is higher 
and the action of the aqueous vapour more prolonged. According to 
Bucholz, ferrous oxide is produced. 

6. At ordinary temperatures, and out of contact of air, iron does not 
decompose thoroughly boiled water, unless it is in contact with more 
electro-negative bodies, as with previously formed ferric oxide, mercury, 
&c.: in this case, and likewise when the liquid is heated to 50^ or 60"", a 
feeble evolution of hydrogen takes place, and ferroso-ferric oxide appears 
to be formed. (Hall, Quart. J. of Sc, 7. 55; Quibourt, Ann. Okim. Phys. 
11, 43; also J. Pharm. 4t, 241.) 

7. In presence of acids which do not themselves give up oxygen, iron 
qniekly decomposes wfcter, and is converted, with evolution of hydrogen^ 



FERROOtMXIDE. I8t 

into Ivjproas oxide, WhieK ^oiillJines iHth ike iiold. the 6roiati6ti 6i 
lijdrogen takes plaoe even in a<[aeouA eil^rbofiic aeidj bnt it eeises on the 
additioii of lime. 

8. By heated oil of vitriol, by nitric aeid, hypochl6t^ii6 icid, t^nd 
other acids, which retain their oxygen less forcibly — also by hypochlo- 
rites, and, at a red heat, by nitrates> chlorAtes, nitrous gas, &o., iron is 
converted, at the expense of the acid, into ferric oxide. When iron 
filings are gently heated with fnming nitric acid, explosion tftkes plac€f. 

iFor the behaviour of iron with anhydrous sulphuric acid at a red heat» 
I. 178.] 

A. Suh-oxide of Iron ? 

When iron is burnt in the flame of the oxy-hydrogen blowpipe, the 
product of the combustion is not scale-oxide of iroUi as when the metal is 
burnt in oxygen gas> but a fused and somewhat malleable mass, which 
dissolves in hydrochloric acid with evolution of hydrogen, forming a solu- 
tion of ferrous hydrochlorate, and invariably contains 6 '79 per cent, of 
oxygen ; it is therefore Fe*0 or Fe',FeO. (Marchand, J, pr, Ghem, 
18, 184.) 

fi. Fjbrrous-oxide. FeO. 

Frotoxide oflron^ Eiamox^dul, Oxyde-ferreux, 

Formed in the solution of Iron in such aqueous acids as do not easily 
give up their oxygen. 

Not known in the separate state. 

Berzeliufl. 

Lavoisier, Dobe- Bu- / ■ ^ » Gay- 

Proust, reiner. cbolz. earlier, later, Lussac. 

Fe .... 27 .... 77-143 .... 73 .... 76-9 .... 77 .... 77*22 .... 7762 .... 7794 

8 .... 22-857 .... 27 .... 231 .... 23 .... 2278 .... 22*38 .... 2206 

FcoL.. 35 ....100-000 ~. 100 .... 1000 .... 100 .... 100*00 .... 100*00 !... 10000 

(FcO = 339-21 + 100 = 439*21. feerzclius.) 

Comhindtiom. a. With Water. — HydrAtb op Ferrous Oxide or 
Ferrous Hydrate. — Th^nard's statement that this eubstance is a 
peculiar white oxide of a lower degree of oxidation, has been disproved by 
Proust, Bucholz, and more especially by Berzelius. {Schw, 22, 334.) — 
The hydrate is precipitated on mixing a solution of a ferrous salt, per- 
fectly free from ferric oxide, with solution of potash perfectly freed from 
air by boiling, the precipitation being performed in a vessel from which 
the air is excluded. The white flakes which fall must be carefully pre- 
served from contact of air during washing and drying. The vessel in 
which the precipitation by potash is performed must be immediately 
filled up with thoroughly boiled water and then closed. As soon as the 
precipitate has settled down, the liquid is decanted with a siphon, leaving 
only a thin layer above the precipitate; the vessel again filled with boil- 
ing water ponred in very slowly so as not to disturb the precipitate; and 
afterwards shaken and closed. This purification by alternate subsidence 
and decanlation must be perfortned as quickly as possible, because ferrous 
oxide decomposes wat^r by continued contact, and is converted into 



iSB IRON. 

ferroso-ferric oxide. The light green precipitate is then introduced ad 
quickly as possible into a tubulated retort, having its neck fitted with a 
stop -cock from which proceeds a tube 28 inches long, bent downwards, 
and dipping into mercury; ether is ponredupon it; the tubulature closed, 
heat applied till the ether vapour, together with the air of the retort, has 
all escaped through the mercury; and the retort afterwards kept warm 
and the tube cool — so that the water may distil off and condense in the 
tube — till the precipitate is quite dry. The stopcock is then closed, and 
the whole left to cool; after which the retort is filled with hydrogen gas, 
and its contents emptied as quickly as possible, under a bell-jar filled 
with hydrogen gas, into small, wide-mouthed, well-stopped bottles. If a 
ferrous salt be precipitated by excess of ammonia instead of potash, the 
precipitate, after long standing, gives o£f hydrogen gas, becomes gradually 
darker in colour, and when dried in the manner above described, is con< 
verted into black ferroso-ferric oxide containing ammonia. (Gr. Schmidt, 
Ann. Fkarm, 36, 101.) 

Dried ferrous hydrate is a brittle, easily friable mass, of a fine 
green colour. (G. Schmidt.) The green colour is probably due to 
incipient oxidation. It is not magnetic. (W older & Liebig.) On 
exposure to the air, it is instantly converted into ferric oxide, the change 
being attended with an evolution of heat which often rises to redness. It 
absorbs carbonic acid gas with violence, becoming at the same time hot 
and black, and dissolves in aqueous acids with great development of heat. 

iG. Schmidt.) When the liquid in which the white flakes of hydrated 
errous oxide have been precipitated is heated to ebullition, they turn 
black, in consequence (according to Wohler & Liebig) of the formation of 
hydrated ferroso-ferric oxide by the action of the air. The protoxide, if 
exposed to the air while still moist, quickly changes to dingy green 
hydrate of ferroso-ferric oxide, and afterwards to yellowish-brown hydrate 
of ferric oxide. 

5. With Acids, forming the Salts op Ferrous-oxide, or Ferrous 
Salts. Proto-salts of Iron. — The affinity of ferrous oxide for acids is con- 
siderable. Ferrous salts are, for the most part, white when anhydrous, and 
pale greenish-blue in the hydrated state. The soluble salts have at first a 
sweetish, and afterwards an inky taste. They give oflf their acid on ignition 
if the acid is volatile. The residue obtained by igniting a ferrous salt out 
of contact of air, consists of ferric oxide, if the acid — such as sulphuric 
or nitric acid — ogives up its oxygen readily; of ferroso-ferric oxide, if the 
acid, e, g,, carbonic acid, retains its oxygen more forcibly; and of metallic 
iron if the acid is organic. Before the blowpipe, with carbonate of soda, 
borax and microcosmic salt, ferrous salts exhibit the reactions of ferric 
oxide. They extract oxygen from the air and from various oxidized 
compounds — viz., from water iu presence of chlorine, from hypochlorouB 
acid, from nitric acid, and from the oxides of silver, gold, and palladinm 
dissolved iu acids — ^and are thereby converted into ferric salts. If no 
excess of acid is present to hold in solution the whole of the ferric oxide 
thus produced, part of it is precipitated in the form of a yellowish-browA 
basic salt. When nitric acid is the oxidizing agent, so long as any 
portion of ferrous salt remains unconverted into ferric salt, the nitric 
oxide separated from the nitric acid does not escape from the liquid, but is 
absorbed by the excess of ferrous salt and forms a dark greenish -brown 
solution. A concentrated solution of sulphate or hydrocUorate of ferrous 
oxide placed in the circuit of a hundred -pair voltaic battery, deposits 



I 

I 



FERReUS SALTS. 189 

metallic iron in small granules on the negative platinum \vire. If the 
positive wire is dipped into a solution of common salt separated from the 
iron-solution by moist clay, the iron is obtained in glittering crystals 
which exhibit magnetic polarity. (Becqnerel.) Zinc immersed in a 
perfectly neutral solution of ferrous sulphate or hydrochlorate contained 
in a stoppered bottle, throws down metallic iron (together with oxide) 
which is deposited partly on the zinc, partly on the contiguous side of 
the glass. (Fischer, Pogg, 9, 266.) If plates of zinc and copper soldered 
together are immersed in the perfectly neutral hydrochlorate solution, the 
iron is deposited on the copper in the form of a bluish-white, metallic, 
very friable mass, which, when gently ignited in hydrogen gas, becomes 
very tough. (Capitaine, N, Ann, Chim, Fhys. 2, 126.) Anthon (Repert. 
77, 121) obtained with zinc, not metallic iron, but light green flakes of 
ferroso-ferric oxide which gradually acquired a darker colour. [Was the 
air perfectly excluded 1] — Hydrosulphurio acid precipitates only those 
ferrous salts which contain a weaker acid; e, g,, the aqueous acid car- 
bonate, and the neutral oxalate, tartrate, and acetate, the precipitation in 
the three last-mentioned salts, going on only till a moderate portion of 
acid is set free (Gay-Lussac); the same re-agent precipitates the benzoata 
of ferrous oxide, and even, to a slight extent, the sulphate and hydro- 
chlorate, if the acids are completely saturated with base. (Grischow^ 
Schw, 27, 185.) The same result was obtained by Wackenroder 
(iT. Br, Arch. 16, 118), who states that hydrosulphuric acid throws down 
a large quantity of iron from acetate of ferrous oxide, or from the sulphate 
or hydrochlorate mixed with acetate of potash; but not the whole of it, 
even when the acetate of soda is in excess. The black precipitate is 
bydrated protosulphide of iron, which acquires a rustv brown colour by 
exposure to the air. It dissolves readily in hydrochloric or sulphuric 
acid, and likewise in a large quantity of acetic acid, provided it does not 
contain excess of sulphur. (Wackenroder.) The corresponding precipi- 
tates of cobalt and nickel oxidate much more slowly by exposure to the 
air. — The same precipitate, but containing the whole of the iron, is pro^ 
duced in all ferrous salts ou the addition of an alkaline hydrosulphate; 
and it is not soluble in an excess of the re-agent. Hydrosulphate of 
ammonia dissolves a mere trace of it, but gives it up again on exposure 
to the air, or on the addition of hydrosulphite of ammonia. (Wacken- 
roder.) A very dilute iron -solution to which hydrosulphate of ammonia 
is added, assumes a green colour, from the presence of iron in a state of 
suspension. — Fixed caustic alkalis completely precipitate the iron in the 
form of a white hydrate, which, by exposure to the air, acquires a dingy 
green and afterwards a red-brown colour. — Ammonia throws down part 
of the- iron in the form of hydrate, the rest remaining dissolved in the 
liquid, which, when exposed to the air, becomes covered first with a green 
and afterwards with a brown film. If the ferrous salt is previously 
mixed with sal-ammoniac, ammonia yields no precipitate, but forms a 
pale green mixture which exhibits similar appearances on exposure to 
tho air. — Monocarbonate of potash or soda and sesquicarbonate of am- 
monia throw down white carbonate of ferrous oxide, which soon acquires 
a green and afterwards a brown colour by exposure to the air— and if 
sal-ammoniac be added, dissolves in the liquid, which then exhibits a 
green and subsequently a brown turbidity on exposure to the air. Bicar- 
bonate of potash or soda forms the same precipitate, with evolution of 
carbonic acid; but if the solutions are dilute, a clear mixture is formed, 
which deposits ferrous carbonate on boiling, and on exposure to the air. 



ISO IRQN* 

jieldB a precipitate of kjdrated ferroso-ferric oxide. — Carbonate of linxe 
does not precipitate ferrous salts. (Fuchs.) — Phosphate of soda precipi- 
tates (up to a thousand-fold dilution: Ffaff) white phosphate of ferrous 
oxide, which acquires a bluish-green colour by exposure to the air. 
Arseniate of soda precipitates (up to a thousand-fold dilution: Pfaff) 
white arseniate of ferrouji oxide, which becomes dingy-green on exposure 
to the air. — Oxalic acid and add oxalate of potash communicate a yellow 
colour to ferrous salts, and, after a while, throw down yellow oxalate of 
ferrous oxide, the precipitation being immediate when an alkaline oxalate 
is used. — Ferrocjranide of potassium forms a precipitate which is white, if 
the) solution has been perfectly freed from air by boiling and the iron- 
salt is absolutely free from ferric oxide, but otherwise bluish-white; by 
exposure to the air, this precipitate is converted into Prussian-blue. 
Ferricyanide of potassium gives a precipitate of Prussian-blue even in 
yery dilute solutions. — Tincture of galls neither colours nor precipitates 
ferrous salts, when they are quite free from ferric oxide; but the mixture 
acquires a yiolet-black colour on exposure to the air. According to 
Pfaff, tincture of galls gives a purple colour and precipitate with aqueous 
acid carbonate of ferrous oxide. 

Those ferrous salts which are insoluble in water, dissolve in aqueous 
hydrochloric acid. Both the aqueous and the hydrochloric acid solutions 
absorb large quantities of nitrous gas, thereby acquiring a dark brown 
colour, ( Vid. SidphcUe and HydroMoraie of Ferrous-^xide,) 

C. Ferroso-ferric Oxide. 

JBisenoxpdoxydfd, DetUoxyde de Fer, — The name Ferroso-firric oxide 
is applied to oxides of iron which contain more oxygen than the protoxide 
and less than the sesquioxide, and may be regarded as compounds of the 
protoxide and sesquioxide in various proportions. 

a. JScale-oxide. — OFeO, Fe*0^ When iron is heated to redness in 
the air, two layers of scale-oxide are formed, which may easily be sepa- 
rated. The inner layer, 6FeO, Fe'O', is blackish -grey, porous, brittle, 
and attracted by the magnet. The outer layer contains a larger quantity 
of ferric oxide, but in variable proportion; it is of a reddish iron-black 
colour, dense, brittle, yields a black powder, and is more strongly 
attracted by the magnet than the inner layer. The amount of fernc 
oxide in the outer layer is between 32 and 37 per cent., and on the very 
surface it is as much as 52*8 per cent. (Mosander, Fogg. 6, 35; also 
Schw, 47, 81.) Specific gravity of the scale-oxide=5-48. (P. Boullay.) 

Or ! Mosander. Berthier. 

8Fe 216 .... 75 6FeO .... 21d ... 72-92 .... 7256 .... 64-2 

90 17 .... 25 Fe»08 .... 79 ... 2708 .... 2641 .... 35-8 

Silica .... .:.. .... 1*03 .... 

6FeO,FeK)» 288 .... 100 288 .... 10000 .... lOO'OO .... 1000 

Berthier (Ann. Chim, Phy$, 27, 19; also Sckw. 43, 319) regards the 
scale-oxide as 4FeO, Fe'O'; Mosander attributes the greater amount of 
ferric oxide found by Berthier to the fact of Berthier having analyzed the 
inner and outer layers together. 

h. Magnetic Oxide, FeO, Fe*0'. — Found native; likewise in many 
meteorites. — Fovmation. 1.. In the rapid combustion of iron, either in 
oxygen gas or in the air. (Mitscherlich, Fogg. 15, 632.) — 2, By igniting 



FERROSO-FERBIC OXIDE. 191 

iron (or the acale-oxide: Eegnavdt) in an ftimosphere of hydrogen gas, 
(Gay-Luesac, Despretz.) The iron phites which are laid beneath the 
hearths of iron-smelting furnaces and are exposed to a red heat, are, in 
the course of 6 or 10 years, completely converted by the moisture of the 
soil into magnetic oxide, partly crystalline, partly amorphous and attracted 
by the magnet ^but not itself magnetic). The same compound is formed 
on the nnc&r siae of the refining hearths, where the iron comes in contact 
with aqueous vapour. (Koch, Ueber KryslaU, HuUetiproducte, s. 17.)*^ 
By fusing protochloride of iron at a low red heat with dry carbonate of 
soda and extracting the chloride of sodium with water, the magnetic 
oxide is obtained in the form of a black heavv powder. (Liebig & Wbhler, 
-Pogff. 21, 582.) [Is the higher oxidation of the iron in this process due 
to the oxygen of the air or to the carbonic acid of the carbonate of 
soda?] 

The native oxide crystallizes in forms belonging to the regular system; 
Fig, 2, 3, 5, 6, &c. Cleavage indistinct, parallel to o. Harder than fluor* 
spar; sp. gr. 5*094. Fracture conchoidal. Colour iron-black; yields a 
black powder. Fuses more readily than iron; with difficulty before the 
blowpipe. Attracted by the magnet and often itself magnetic. The 
oxide prepared by (2) has a specific gravity of 5*40. Crystallizes in the 
forms represented in figures 1, 4, and 8. (Koch.) 

Gay. 
BerxeUas. Fuchs. Desprets. Lussac. 

Marra. $mtive. prepared by (2) 

3Fe 81 ..,. 71*68 .... 71-86 .... 71*91 .... 72*46 .... 72*5 

40 32 .... 28-32 .... 28*14 .... 28-09 .... 27-54 .... 27*5 

Fe»0*.... 113 .... 10000 .... 10000 .... 100*00 .... 100*00 .... 100*0 

Berzelius. Fuchg. Desprets. Gay-Lussao. 

Kura. native, Brazil. Schwarzenstein. 

FeO 35 .... 30*97 .... 31 .... 30*88 .... 20 .... 25 

Fe^O* 78 .... 6903 .... 69 .... 68-40 .... 72 .... 75 



FeO,Fe«03 113 .... 100*00 .... 100 .... 99*28 .... 100 .... 100 

(Fe»0« == 3 . 339-21+400 = 1417*63. Beneliai.) 

The analysis of the magnetic oxide from Schwarsenstein corresponds to 
the formula 3FeO,4Fe'0', probably because the ore contains specular 
iron mixed with it. (Von Kobell, Schw, 62, 195; 64, 429; J. pr. Ohem. 
1, 86.) [For Karsten*s analyses of various kinds of magnetic iron-ore 
vid. Karsten's Arch, /. Bergh. u. ffuUenk, 16, 17.1 — On the hearths of 
puddling furnaces there is formed a mixture of ferrous silicate and 
magnetic oxide; the latter is found crystallized in geodes of regular 
tetrahedrons, truncated octohedrons, and rhomboidal dodecahedrons; 
these crystals dissolve in hydrochloric acid, with separation of gelatinous 
silica, and contain 35 per cent, of ferrous oxide, 58 p. c. of ferric oxide, 
and 7 of silica. (Laurent & Holms, Ann, Chim. Phys, 60, 330; also 
J. pr, Chem. 7, 339.) Probably a mixture of 3(FeO,Fe«0') and FeO,SiOl 
Decompositions of Ferroso- ferric Oxide. — Reduced to the metallic state 
by oharcoal at a white heat. Pounded scale-oxide ignited in a charcoal 
crucible is converted on the outside into soft pulverulent metallic iron of 
a blackish-blue colour; further inwards is found olive-green iron which is 
very pure, and free from carbon and oxygen; and finally in the middle 
there is formed a mixture of olive-green iron and undecomposed scale- 
oxide; no free protoxide is foond in any part of the mixture.— -2. To 



i9i IRON. 

the metallic state by hydrogen gas at all temperatures between 400^ and 
the strongest heat of the wind-furnace; generally, at the same temperatare 
as water, on the other band, is decomposed by metallic iron. (Gay-Lnssao; 
eomp. I. 125.) — Ammoniacal gas likewise reduces the iron at a red-heat. 
"^Ferrum pidveratum might perhaps be best prepared by reducing 
scale-oxide with hydrogen gas in an iron tube. — 3. Carbonic oxide gas 
acts like hydrogen; it reduces red-hot ferroso-ferric oxide to the metallic 
state, with formation of carbonic acid, and, on the other hand, carbonic 
acid is reduced by iron to the state of carbonic oxide, with formation of 
ferroso-ferric oxide. (Despretz, Ann, Chim. Phys, 43, 222: also Poff§^. 
18, 159; Gbbel, J,pr. Chem, 6, 386; Leplay & Laurent, Ann. Chim, Pkys. 
65, 404.) — Carbonic acid e^as mixed with an eqnal volume of carbonic 
oxide likewise converts red-hot iron into ferroso-ferric oxide. (Laurent, 
j4nn, Chim, Phy$, 65, 423.) — 4. Potassium and sodium at about 300® 
likewise reduce ferroso-ferric oxide to the metallic state, the reduction 
being attended with a slight evolution of light and heat. — 5. By ignition 
with sulphur, this oxide yields sulphurous acid and sulphide of iron.— 
6. When finely pulverized and treated with a quantity of dilute hydro- 
chloric acid, less than sufficient to dissolve it completely, it is resolved 
into ferrous oxide which dissolves, and red ferric oxide which remains 
undissolved. (Berzelius, Sclvw, 15, 291.) 

Combinations. — a. With Water. — Hydrate op Ferroso-ffiiric 
Oxide. — a. Dingy-green Hydrate, — By exposing the white hydrate of 
ferrous oxide to the air for a short time, — or by precipitating a mixture 
of a ferrous salt and a small quantity of ferric salt with potash or 
ammonia — a dingy green hydrate of ferroso-ferric oxide is obtained, 
which, on further exposure to* the air, is quickly converted into rusty 
brown hydrate of ferric oxide. 

&, Black Hydrate, — Precipitated from a solution of mairnetic oxide in 
hydrochloric acid, or from a mixture of ferrous and ferric salts containing 
1 At. FeO to 1 At. Fe'O', on the addition of potsish or ammonia. The 
yellow solution of magnetic oxide in hydrochloric acid yields with 
ammonia a brownish-black precipitate which is magnetic even while in 
the liquid, so that it collects round a magnet dipped into that liquid. 
It may be washed on the filter without becoming more highly oxidized. 
(Liebig k Wiihler, Fogg, 21, 583; also Mag. Pkarm. 34, 138.)— 2. The 
same precipitate is obtained by mixing sulphate of ferric oxide and 
ammonia with sulphate of ferrous oxide, in such proportion that the ferric 
oxide present in the mixture may contain three times as much oxygen aa 
the ferrous oxide, and precipitating with ammonia. If the quantity of 
ferrous sulphate is greater than the above, the precipitate will contain an 
excess of hydrated ferrous oxide, which will oxidate more quickly; if, 
on the contrary, the ferric salt is in excess, the precipitate will contain 
free hydrated ferric oxide, from which the hydrated ferroso-ferric oxide 
may be separated by the magnet. (Abich, Fogg, 23, 354.) — 3. Two 
equal portions of ferrous sulphate are taken; the first is dissolved in 
water acidulated with sulphuric acid, nnd oxidated at a boiling heat by 
the addition of nitric acid in small portions at a time. The other portion 
is dissolved in water freed from air by boiling. The two solutions are 
then mixed; the mixture, while still hot, precipitated by ammonia added 
at once in excess; and the liquid, together with the brown-black preci- 
pitate, heated for some minutes to the boiling point. The precipitated 
ferroso-ferric oxide is then collected on a filter and washed—curing 



PERROSO-FERRIC OXIDE. 193 

which process it undergoes further oxidation — and then dried at a gentle 
heat. (Wdhler, Ann, Pharm. 22, 5Q.) [This process should yield 
2FeO,Pe^O^; but even if a greater quantity of ferric oxide is not produced 
b^ the nitric acid still remaining, or by contact with the air, the propor- 
tion of that oxide is sure to be increased by decomposition of water.] 

Mercer {Fhil. Mag. J. 20, 340) adopts the same process, excepting that 
he boils the liquid down so as to expel any accidental excess of nitric 
acid and precipitates by potash at a boiling heat instead of by ammonia. 
The precipitate when examined by the microscope appears to consist of 
brown transparent lauiinso. — 4. Bottger {Beitrage, 2, 12) precipitates 
ferrous sulphate free from ferric oxide by the addition of carbonate of 
soda; washes the precipitate several times by decantation; and then boils 
it with tolerably concentrated caustic potash. . This process yields a 
velvet-black powder, much less liable to absorb an additional quantity of 
oxygen than that which has been precipitated by ammonia. [No hydrt>gen 
is evolved on boiling the precipitate with potash out of contact of air, 
and the precipitate remains greyish-white. Gm.] — 5. Noel(y^,J. Fharm, 
1, 62) precipitates ferrous sulphate with carbonate of soda, washes the 
ferrous carbonate by decantation, leaves it to drain upon linen, and then 
heats it in a cast-iron vesesl, with constant stirring, till it is dry. It is 
thereby converted into a velvet-black powder. Soubeiran obtained by 
this process a precipitate which was not perfectly black, and when 
treated with hydrochloric acid, evolved carbouic acid. — 6. Preuss intro- 
duces 4 parts of pulverized iron and 5 parts of ferric oxide into a flask, 
together with a two or threefold quantity of water, and boils the liquid 
gently for some time. The mixture gives off fetid hydrogen gas and 
turns dark brown at first, but afterwards black. When the evolution of 
gas ceases and the resulting black powder settles down readily, it is 
separated by levigation from the excess of iron; thrown on a filter of 
grey porous paper; and the filter, after the water has drained ofiT, is 
wrapped up in a large quantity of paper, and quickly dried in hot air. — 
The black, very loose powder dissolves in acids without evolution of gas, 
and the solution yields a black precipitate on the addition of an alkali. 
The precipitate must not be dried by heat, because in that case it would 
turn brown from higher oxidation. In the formation of ferroso-ferric 
oxide by this process, the ferric oxide does not give up oxygen to the 
iron, but induces the decomposition of the water, by its predisposing 
affinity for ferrous oxide. Zinc is not oxidated by boiling with water 
and hydratcd ferric oxide; the hydrates of alumina and chromic oxide 
exhibit a similar disinclination to oxidate iron. (Wohler, Ann. Pharm. 
28, 92.) 

The black hydrate of ferroso-ferric oxide exhibits, after drying, the 
appearance of brown-black, brittle, strongly magnetic lumps, having a 
conchoidal fracture and yielding a dark brown powder. It contains 
about 7 per cent, of water, which it gives off when heated in a retort, 
leaving black anhydrous ferroso-ferric oxide. When heated in the air it 
is converted into ferric oxide. From its yellow solution in hydrochloric 
acid, it is precipitated unchanged by ammonia. (Wbhler.) 

Iron-^lack or jEfhiops martialis Lemeryi is a mixture of ferric and 
ferrous oxides, in different proportions, according to the mode of prepara- 
tion, and partly hydrated. 

Anhydrous uEthiops is obtained by the following methods: 1. By 
passing aqueous vapour over red-hot iron, or sprinkling red-hot iron 
tilings or nails repeatedly with wateii till they become friable. This 

VOL. T. o 



194 ntoH. 

method yields FeO^FeH)*. — 2. An intimate mixture of palrerited ireft 
and feme oxide is tightly pressed into a eracihle, the cover put on, 
and the whole exposed for two hours to an intense heat. To obtain 
FeO,Fe*0' by tliis process, the proportions required are S:7 pts. (I At.) 
iron, 312 pts. (4 At ) Fe'O^. Vauquelin and Bncholi, with the view of 
obtaining pure ferrous oxide, prescribe 95 parts (rather more than I At.) 
of ferric oxide to 27 pts (i At ) of iron; in that case, the products must 
contain metallic iron. — 3. Hyd rated ferric oxide is mixed with a sufficient 
quantity of olive oil to form it into a moist fH>wder, and then ignited in a 
covered crncible or in a retort- '1 he anhydrous oxide may likewise be 
used instesid of the hydrate, and wax or vine^^ar instead of oil : vinegar 
if used must be added in large quantity, the mixture subsequently 
distilled, and the residue .heated to redness. The charcfMil which remains 
on iL'tiitino^ these substances, serves for the partial reduction of tlie ferrio 
oxide. If the quantity of organic matter is too small, part of the ferrie 
oxide remains unaltered; if it is too great, an excess of charcoal is pro- 
duce<l, and part of the ferroso-ferric oxide is thereby reduced to th« 
metallic state. 

JI^drate<l ^tkiops.-^l. Iron-filings are placed in a wide vessel and 
covered with a deep stratum of water; the whole is exposed to the air for 
a considerable time and frequently stirred; and the lighter black powder 
which forms, decanted from time to time from the remaining iron filings, 
then quickly eollecteil on a filter, and rapidly dried at a moderate heat. 
(Leraery.) If the filings are moistened with only a small quantity of 
water, and the mixture agitated, the oxidation goes on much more rapidly 
and is attended with evulutiun of heat, so that It becomes necessary to 
replace the water as it eva))orates; after ^y^ days the vthiops may 
be removed by levigation. ^Cavezsali.) This preparation is doubtless 
identical with the black hydrate of ferroso-ferric oxide already described 
(p. 192), and the much more expetiitious modes of forming it^ recommended 
by Pre u 88 and Wohier^ are to be preferred. 

5. With Acids, forming the Salts, of FEnRoso-FBRRic Oxide, or 
Ferroso-fkrkic Salts. — These salts are obtained by partial oxidation of 
ferrous salts, or partial de oxidation of ferric salts, or by mixing ferrous 
salts with ferric salts, or by dissiilving ferroso-ferric oxide in acids. 
They are mostly of a bright green, brownish, or yellow colour, and have 
a ferruginous taste. Like the ferrous salts, they are converted into ferric 
salts by oxidation. Many oxidable substances^ on the contrary, such as 
sulphuretted hydrogen, metals, «kc., convert them into ferrous salts by 
withdrawing a portion of their oxygen. They may be regarded as mere 
mixtures of ferrous wiih ferric salts, and exhibit many reactitms belonging 
to one or the other of these salts. They are characterized by the green, 
black, or — if a large quantity of ferric salt is present — the brown-black 
precipitate which they form with alkalis, and the blue with cyanide of 
potassium. They resemble the ferrous salts in giving a blue precipitate 
with ferricyanide of potassium, and the ferric salts in their behaviour with 
mecouic acid, gallic acid, hydrosulphocyanic acid, and ferrocyanide of 
potassium. 

D. Ferric Oxide. Fe*0*. 

Sesquioxide of Iron, Peroxide of Iron, Red Oxide of Iron, Oecnre in 
the forms of Specular Iron or Iron-glance, Eed HofmcUiU or Med 
Iron-stone, and Martite, 



FERBIC-aXIDS. 195 

Preparation, 1 . By i^iting the metal ar ferroso-fenio oxide for a 
Gonsiderable time in contact with air : Crocus Martis ailftringens, — 2. Bj 
igniting hydrated ferric oxide.- 3. By strongly igniting calcined green 
ritriol, or disulphate of ferric oxide : Colcothavy Caput mortuum Vkrioli. 
— 4. By oxidating iron with nitric acid, then evaporating to dryness and 
igniting. — 5. By deflagrating 1 part of iron filings with three parts of 
nitre, and extracting the potash with water: Crocus Martis ZwelfeH. 

Properties, The primary form of specular iron is an acute rhombo- 
hedron, Fig. 1.51; also Fips. 153, 155, 156» 157; r*:r*= 87** 9'; r :/^or 
f*=r02^5'; somewhat deavable parallel to r, (Hauy.) Sp. gr. 5'2'31 
(Mohs); 5*19. ..623 (G. Rose). Softer than quartz; 6teel>grey, yielding 
a brown-red powder. In thin laminsB, as it occurs in micaceous iron-ore, 
it transmits light of a red colour. Red haematite is generally of fibrous 
texture, less hard, of brown-red colour, and mostly has a densiit^ of 4*7. 
— Martite, although it consists of pure ferric oxide, crystallizes in regular 
octohedrons, probably therefore exhibiting a case of dimorphism. (Kubell, 
iSckw. 62, 196.) — Artificial ferric oxide, obtained by strong ignition of the 
sulphate or nitrate, is steel grey and metallic; sometimes, when it is 
produced by heating the sesquichloride of iron in vessels containing air, 
it forms a sublimate consisting of laminoB, identical with those of micar 
ceons iron-glance {Fiff. 153, with the p faces enlarged); and appears red 
by transmitted light. The same laminie are formed in pottery-furnaces in 
which the ware is glazed with common salt. (Mitscherlich. Pogg. 15,630.) 
IT The specific gravity of artificial ferric oxide ignited over a spirit lamp^ 
is 6*17; after ignition oyer a charcoal fire, 5*04. In the pottery-furnace^ 
it melts, but is at the same time partly converted into ferrooa oxide. 
(H, Rose, Pogg. 74, 440.) IT 

Bu- Gfty- Stro* Ber* Dobe* Thom- 

cholz. Lussac. meyer. zelius. rdner. son. 

2Pe 64 .... 69-23 .... 7042 .... 70-27 .... 69-85 .... 69-22 .... 69 .... 68*965 

30 24 .... 30-77 .... 29-58 .... 29*73 .... 3015 .... 3078 .... 81 .... 31-035 

Fe»0" .... 78 ....100 00 .... 10000 ....10000 ....10000 ....10000 ....100 .... 100000 

(Fe^O* = 2 . 339-21 + 300 ~ 978*42. Benelias.) 

Decompositions, 1. By gentle ignition with charcoal, it is reduced to 
ferroso-ferric oxide; by stronger ignition, to the metallic state. — Ferric 
oxide, heated to whiteness in a charcoal crucible, yields metallic iron at 
the part wbich is in contact with the charcoal lining, but not till the 
rest of the oxide, to the very centre, is reduced to the state of ferroso- 
ferric oxide. (Berthier.) This reduction of the part of the oxide not in 
contact with the charcoal, to the state of ferroso-ferric oxide, is due to the 
action of carbonic oxide gas. If two platinum crucibles, the one contain- 
ing a piece of charcoal, the other a piece of iron -glance, be placed at a 
dis^tance from one another in a porcelain tube closed at one end, and the 
whole ignited, carbonic oxide and carbonic acid gases are evolved, and 
the iron-glance reduced to the metallic state. For the oxygen of the air 
in the tube combines with the charcoal and forms carbonic oxide gas, 
which is converted into carbonic acid by the ferric oxide, and subse- 
quently bronglit ba«k to the state of carbonic oxide by the charcoal, and 
so on. If the tube is filled with nitrogen gas, the reduction is much 
slower; in this case, the small quantities of oxygen and hydrogen in the 
charcoal, which are set free in the forms of carbonic oxide and hydrogen 
gas, serve to induce the reduction. (Leplay 4 Laurent^ Ann, Chun, Ph^s^ 

o2 



196 IIKOK. 

95f 403; also J. pr, Chem. 18, 284.) — The peculiar circumstanoe in 
Berthier*8 experiment of the non-production of metallic iron till all the 
ferric oxide had heen converted into ferroso-ferric oxide, cannot he ex- 
plained hy the penetration of carhonic oxide gas from the carhonaceoos 
envelope to the interior; for carhonic oxide could not penetrate the 
ferroso-ferric oxide without reducing it to the metallic state; the reduc- 
tion must therefore he a transposition of atoms, like that which occurs 
in galvanic decompositions, wherehj the oxj^^en of the ferric oxide is 
transferred from the interior towards the carbonaceous envelope. For 
copper, likewise, when surrounded with cupric oxide and ignited, is 
converted, even to a considerable depth, into cuprous oxide, to which 
state the cupric oxide is also reduced, — and this effect takes place with- 
out the co-operation of any gas. (De^en, Ann. Pharm, 29, 261.) — 
Becquerel {Ann, Chim. Phys. 49, 131) likewise supposes a galvanic 
motion of this nature to take place in Berthier^s experiment. 

Since, according to Laurent {Ann. Chim. Phys. Q5f 404), carhonic 
oxide gas, mixed with an equal volume of carhonic acid, merely reduces 
ferric oxide to ferroso-ferric oxide, the explanation of Leplay k Laurent 
may still hold good, if we are at liberty to suppose that the diffusion of 
the gases in the pulverulent mass of ferroso-ferric oxide takes place 
quickly enough to transfer the carbonic acid gas produced in the interior 
towards the charcoal envelope, in quantity sufficient to interfere with the 
reducing action of the carbonic oxide which diffuses itself from without 
inwards, — that reducing action, moreover, being in itself but feehle. — 
Ferric oxide ignited with carbonate of soda on charcoal before the blow- 
pipe, sinks, together with the carbonate of soda, into the charcoal, and 
is easily reduced to a metallic powder, which may be separated from the 
charcoal by pounding and levigation. (Berzelius.) — 2. A stream of car- 
bonic oxide gas reduces ferric oxide heated to redness in a tube, first to 
ferroso-ferric oxide, and afterwards to the metallic state. (Gobell, J. pr. 
Chtm. 6, 386; Gm.)— Proust {Scher. g. 10, 113; also GUb. 25, 16) and 
Nasse {Schw. 46, 73) found ferric oxide reduced to the metallic state in 
a pottery-furnace, doubtless by the action of carbonic oxide gas. — Proust 
also found that ferric oxide was reduced to ferroso-ferric oxide when 
ignited in crucibles (into which the carbonic oxide from the fire could 
penetrate), hut not when heated in a coated retort. — 3. Hydrogen gas 
acts like carbonic oxide. The reduction begins somewhat above the 
hoiling point of mercury. (Magnus.) — Ammoniacal gas likewise reduces 
ferric oxide to the metallic state. — 4. Ferric oxide ignited with sulphur 
yields sulphurous acid and sulphide of iron. — It is not reduced by a 
boiling solution of protochloride of tin. (A. Vogel. Kastn. Arch. 23, 85.) 

Combinations, a. With Water. Hydrated Ferric Oxide, or 
Ferric Hydrate. — Found native in the form of Broton Iron-ore^ &c. 
Many kinds of brown iron-ore appear to be formed by the deposition of 
hydrated ferric oxide from water containing ferrous carbonate in solution, 
as it issues out of the earth and evaporates in the air. If this water 
gives off its carbonic acid out of contact of air, it deposits monocar- 
bonate of ferrous oxide in the form of Sj)hcBroBiderite. (Bischoff, Schw. 68, 
420.) Much hydrated ferric oxide has likewise been produced by the 
action of the air on ferrous carbonate and sulphide of iron. — Prepara^ 
tion. 1. By exposing iron moistened with water to the air for a consi- 
derable time: Iron-rust, Crocus Mart is aperitivns. — 2. By exposing 
hydrate or carbonate of jferrous oxide^ obtained by precipitating green 



FERRIC OXIDE. 197 

▼itriol with a caoatic alkali or alkaline carbonate and afterwards washed, 
to the air wLile jet moist. — 3. By precipitating a ferric salt with excess 
of caustic alkali or alkaline carbonate. According to Berzelius, the pre- 
cipitate thereby obtained always contains more or less of the alkali em- 
ployed. — The native hydrate is brown or yellow, crystallized in thin 
tables, capillary, fibrous, compact, conchoi<lal or ochrey. — Iron-rust and 
the hydrate obtained by (2) are yellowish-brown, friable, earthy masses. 
The hydrate precipitated by ammonia dries up to a compact brown mass 
having a shining, conchoidal fracture. — If any of the looser varieties of 
the hydrate, either natural or artificial, are gently heated (not to redness) 
80 as to expel the water, and the remaining oxide is then more strongly 
heated, it becomes incandescent without further loss of weight, and i s 
afterwards less soluble in acids. (Berzelius.) . 

There are several varieties both of the native and of the artificia 
hydrate, difiering not only in external appearance, but likewise by th^ 
quantities of water which they contain. According to the analyses 
hitherto given, the following varieties may be distinguished : 

a, Fe'0*,HO. — To this head belong: a. Needle iron-ore from Ober- 
kirchen. (It is amorphous with Manganite [IV, 203] of specific gravity 
4*32, and contains 10 percent, of water: Breitkaupt.) — b, Gbthite (Pyro- 
9iderite, Ruby mica) from Eisenfeld in Nassau. — c. Lepidokrokite from 
the Hollertenzug in the Westerwald. (In a specimen of this mineral 
from Hamm, Breithaupt found 14'32 per cent, of water, and in one from 
Baden 13*49 percent.) — d. Brown Ir&n-ore from Saxony in pseudo- 
crystals of iron-pyrites. According to Kobell {J. pr, Ckem, 1, 181) the 
brown Haematite from Maryland and that from Beresof have a similar 
composition.-—^. The same from Orenburg. (The. so-called mineral hail- 
stones.) 

Kobell. Hermann. 

a. b, c. d, e, 

Fc«0» .... 78 .... 89-65 .... 90-53 .... 86*35 .... 85-65 ... 86*34 .... 90*02 

HO 9 .... 10*35 .... 9*47 .... 11*38 .... 11*50 .... 11*66 .... 10'19 

SiC)« .... trace .... 0*85 .... 0*35 .... 2*00 

CaO .... .... trace .... trace 

MnW .... .... .... 0*51 .... 2*50 

Fe^O^.HO 87 ....100*00 .... 100*00 .... 100*00 .... 10000 .... 100*00 ....100*21 

ff. 2Fe'0',3H0. — a. Fibrous Brown Iron-ore or Brown ffcematite from 
Yicdessos. — 6. The same from Kamensk. — c. The same from Horhausen. 
According to Breithaupt, brown haematite contains on the average 39*59 
per cent, of water, and likewise a small proportion of silica which remains 
as a gelatinous residue when the mineral is dissolved in acids, and appears 
to be an essential constituent of fibrous brown iron-ore. — d. Compact 
Brown iron-ore from Pr. Minden, in pseudo-crystals of iron-pyrites. — 
C^ Iron-rust, prepared according to (I). 

Daabis- Ko- Schon- 

son. bell. berg. Kobell. BerzcUos. 

a. h, c. d, e, . 

2Fe?0» 156 .... 85*24 .... 82 .... 83*38 .... 8227 .... 82*24 .... 85*3 

3HO 27 .... 14*76 .... 14 .... 15*01 .... 13-26 .... 13*26 .... 14*7 

SeO« .... 1 .... 1-61 .... 4*50 .... 4*50 

Mn'O' .... .... 2 

?Fc«0»,3H0 183 ....100-00 .... 99 .... lOO-O? .„. 100-03 .... 100 00 .... 100*0 



198 IRON. 



y. Pe'0*,2H0. — a. Violet-brown fibrous brown iron-ore from Raschan; 
ep. gr. 3 "34. — 6. The hydrate precipitated by ammonia from ferric hydro- 
cblorate and dried at 100^ The loss by ignition may arise from a small 

?aantity of ammonia as well as water. — o. 'Ihe same dried in the sun 
the composition of this nearly corresponds to the formula Fe'0^3H0). 

Brdthaupt. Qm. Berthier. 

a. b, c, 

Fe»0» 78 .... 81-25 .... 803 .... 8149 .... 72 

2HO 18 .... 18-75 .... 19-7 .... 18 51 .... 28 

Fe«0»,2HO 96 .... 100-00 .... 100-0 .... 100-00 .... 100 

^ According to Schaffner (Ann. Pharm. 51, 117), the hydrate obtained 
by precipitating hydrochlorate of ferric oxide with ammonia, contains 
89 '74 p. c. ferric oxide and 10*26 water, numbers which agree with the 
formula Fe*0' + HO. The same hydrate is also formed by exposing 
ferrate of potash to the air. According to Wittstein (Buchnor s Repaid 
43, 367), hydrated ferric oxide, when first precipitated, contains 3 atoms 
of water, Fe'0',3H0, and in that state is easily soluble in acetic or citric 
acid, and wiien examined by the microscope presents the appearance of 
an amorphous powder. But after being kept for some time under water, it 
acquires a crystalline structure, and becomes much less soluble in acids. 
In this state, it is found to contain half as much water a« before, being, 
in fact, composed of 2Fe»0',3HO. IT 

5. With Acids, forming the Salts of Ferric Oxide, or Ferric 
Salts. — Per-salts of Iron. — The affinity of ferric oxide for acids is much 
less than that of ferrous oxide. Crystallized and ignited ferric oxide 
dissolves very slowly in acids; the hydrate dissolves easily. Ferric salts 
are likewise produced by exposing ferrous and ferroso-ferric salts to the 
air, or by heating them with nitric acid, or by bringing them in contact 
with chlorine- water, or with other bodies containing oxygen; also by 
dissolving iron in nitric acid, or in another acid mixed with nitric acid 
and heated. — The dehydrated salts of ferric oxide containing 3 atoms of 
acid are mostly white; the hydrated and the more basic salts are generally 
brown or brownish-yellow; those which are soluble have an inky taste, 
more astringent than that of the ferrous salts. They give olF their acid, 
if it is volatile, at a red heat, and exhibit before the blowpipe all the 
reactions of ferric oxide. One atom of ferric oxide requires 3 atoms of 
acid to form a normal salt, and the salts thus formed are for the most 
part soluble in water, and when dissolved, redden litmus. Many of thej«e 
solutions, when deprived of part of their acid by an alkali, acquire a 
darker red-brown colour, and if subsequently boiled, deposit hydrated 
ferric oxide or a basic salt. (Herschel, 2'offg. 25, 628.) The ferric oxide 
is precipitated in greater quantity as the soluticm is more dilute. If, for 
example, ammonia he added to a dilute solution of a ferric salt, till the 
liijuid is jierfecily neutral, ferric oxide is deposited on the application of 
heat; and if the liquid be again neutralized after cooling, it will yield a 
fresh precipitate of ferric oxide when heated — and so on, till all the oxide 
is prec'pitated. The complete precipitation of the ferric oxide may be at 
once effected by heating the iron solution to the boiling point, and mixing 
it with dilute ammonia till it no longer reddens litmus, or till it acquires 
a very slight alkaline reactfon; under these circumstances, the protoxides 
of manganese, nickel, cobalt, and likewise of cerium, are retained in solu- 
tion. (Herschel, Phil, Trans, 1821, 293; also Ann. Chim, Phya, 20, 



FERRIC SALTS. 199 

d04; ftlMtn Sek». dt, 452.) The Bolntion maj also be neutralized with 
potash, then lar^elj diluted and boiled. A solution of the sulphate ia 
nesi adapted to the purpose, because the basic sulphate of ferric oxide, 
which is at first precipitated, is insoluble in water, whereas the basio 
hydroehlorate is slightly soluble, and the basic nitrate more so. (iM. 
Sheerer, Po^y. 49, S06.) Metallic iron immersed in ferric salts protected 
from the air, converts them into ferrous salts : e. g. 

Fe-0»,3S0' + Fc = 3(FeO,SO»). 

The same effect is produced by other metals, even by silver at a boiling 
heat, whereas, at ordinary temperatures, a ferrous salt by contact with a 
silver-ealt is converte<l into a ferric salt, and silver is precipitated in the 
metallic state (I. 132 ) — Phosphorous acid converts ferric into ferrous 
salts, with formation of phosphoric acid, slowly in the cold, immediately 
on the application of heat. (Berthier, .-inn. Ghim, Fkys. 50, 363 ) Phos* 

f»horie oxide forms a white precipitfite with hydroehlorate of ferric oxide. 
Leverrier.) — Sulphurous acid reduces ferric salts to the state of ferrous 
salts with great facility, especially if the solution is heated. (A. V5gel, 
J. pr Chem. 29, 281.) The effect observed by R. Phillips {Phil. Mag. J. 
2, 75), that sulphurons aci<l imparts to ferric sulphate a deep red colour 
which disappears in a few hours without reduction of the salt, must be 
attributed to the presence of nitric acid, inasmuch as he used ^reen vitriol 
oxidized by boiiiiig with nitric acid. — Protochloride of tin likewise 
reduces ferric to ferrous salts; so also does trithionic acid. (Persoz.) — A 
dilute solution of ferric chloride imparts a blue colour to an alcoholic 
solution of gniac-resin. (Unverdorben.) — Hydrosulphuric acid converts 
ferric salts which contain one of the stronger acids into ferrous salts, with 
precipitation of sulphur. In a solution of the hydroehlorate but not in 
the acid acetate) a small quantity of sulphuric acid is produced, even in 
the cold. (H. Rose, Pogg. 47, 161.) If the ferric oxide is dissolved in a 
weaker acid, sulphuretted hydrogen throws down a black precipitate of 
hydrated sesquisnlphide of iron : e, g., from the solution of ferric oxide in 
vegetable acids, such as acetic acid, when the acid is not in excess; or 
from a solution of the oxide in a mineral acid mixed with acetate of soda; 
part of the iron, however, always remains dissolved in the form of ferrous 
oxide. (Wackenroder, N. Br. Arch, 16, 11 H.) Alkaline hvdrosulphates 
precipitate the iron completely — in the form of black hydrated sesqui- 
sulphide, if the iron-salt is fK)ured into an excess of the alkaline hydro- 
sulphate, but as a mixture of hydrated 8e>quisulphide and sulphur, in the 
contrary case The precipitated scsquisulphide is insoluble in excess of 
the alkaline hydrosulphate; if, however, the solution is very dilute, a 
small quantity of the sulphide remains dis'«dved, imparting a irreeu culour 
to the liquid (H. Rose), and is di'posited on exposure for some time t'* the 
air, or on the addit'on of hydrotiulph !te of ammonia. (Wackenroder.) 
The precipitated sulphide acquires a rusty bn»wn colour when exposed 
to the air; it dissolves easily in mineial acids, but not in acetic acid. 
(Wackenroder.) — An aqueous solution containing not less than I part of 
iron in 100,000 parts of water gives a black precipitate with hydrosul- 
phate of ammonia; with 200,000 )mrts of water, a dark ^'reen mixture is 
produced; with 400,000 pts. a greyish-green; and with ^00,000 pts. of 
water, a greyish-green colour after a few minutes. A similar effect is 
produced by hi hydrosulphate of potash. (Roth, Nepfft. 47, 3<>8. ) Hypo- 
sulphite of soda produces with ferric salts a blackitfb-red colour, which 
disappears in a few honrs; the ferric salt being reduced to the ferrous 



200 IRON. 

state. (Lenz, Ann. Pharm. 40, 101.) The red colouring is produced 
even when the liquid is quite free from nitric acid, and it disappears in a 
few seconds. (6m.) The hydrated sulphides of manganese, cobalt, and 
nickel throw down sesquisulphide of iron from a solution of ferric hydro* 
chlorate. (Anthon.) 

All caustic alkalis added in sufficient quantity to ferric salts, throw 
down yellowish-brown flakes of hydrated ferric oxide, which, according 
to Berzelius, carries more or less of the alkali down with it, and is inso- 
luble in excess of the alkali, if According to Schaffner, hydrated ferric 
oxide precipitated by ammonia is perfectly free from that alkali, so that 
when it is ignited with carbonate of lead-oxide in a tube, the giis which 
escapes passed into hydrochloric acid, and the liquid afterwards treated 
with chloride of platinum, not a trace of chloroplatinate of ammonium is 
obtained. — ^According to Wittstein, hydrated ferric oxide is slightly 
soluble in strong caustic potash; Schaffner, on the other hand, is of 
opinion that the oxide supposed to be dissolved by the potash is merely 
in a state of fine mechanical suspension IT. — The monocarbonates of 
ammonia, potash, and soda, and likewise the bicarbonates, yield the same 
precipitate as the caustic alkalis; it is, however, of a lighter brown colour 
(becoming darker on boiling); contains a small quantity of carbonic acid; 
and if the liquids are somewhat concentrated, dissolves in excess of the 
alkaline carbonate, forming a red-brown solution. The precipitate is not 
dissolved on passing chlorine gaa through the liquid. (Wackenroder.^ — 
The carbonates of baiyta, lime, magnesia, manganous oxide, zino-oxide, 
and cuprio oxide, likewise precipitate ferric oxide completely, even at 
ordinary temperatures; any ferrous oxide that may perchance be present 
remains dissolved, unless the liquid is heated to the boiling point. (Fuchs, 
Schw, 62, 184; v. Kobell. J, pr, Chem. 1, 80.) Carbonate of strontia acts 
in the same manner. (Demar^ay, Ann, Pharm. 11, 240.) — Phosphate of 
soda throws down white phosphate of ferric oxide (even to the fifteen- 
hundredth degree of dilution : Pfaff) which turns brown when treated 
with ammonia, and, if the phosphate of soda is in excess, dissolves in 
ammonia, formiu? a red-brown solution. — Arseniate of soda- throws 
down white arseniate of ferric oxide (even when the solution is diluted 
20,000 times : Pfaff), — A solution of ferric hydrochlorate mixed with 
acetate of soda or formiate of potash, deposits the whole of the iron, on 
boiling, in the form of a precipitate which re-dissolves as the liquid cools, 
or on being washed with cold water. (Liebig, Ann, Pharm, 17, 51.) — 
Alkaline succinates and benzoates, give a light reddish-brown precipi- 
tate with ferric salts (up to the 5000th degree of dilution : Pfaf), provided 
no excess of acid is present. — Tincture of galls imparts a bluish-black 
colour to ferric salts, and then precipitates them. With ferric hydro- 
chlorate the precipitation takes place up to the 120,000th degree of dilu- 
tion {Pfaff) j with 1 part of iron in 200,000 parts of the solution, a bluish- 
black tint is still produced; with 1 pt. of iron in 400,000 pts. of the solu- 
tion, a greenish blue; and with 800,000 pts. of water, the last-mentioned 
colour appears after a few minutes. (Roth.) The limit of the reaction is 
attained when I part of ferric oxide (in the state of sulphate) is contained 
in 300,000 parts of the solution. (Hartig, J. pr. Chem. 22, 51.) If the 
iron-salt contains an excess of one of the stronger acids, no precipitation 
takes place unless acetate of potash is added; the bluish-black precipitate 
dissolves in hydrochloric acids, and acquires a dark purple-red colour on 
the addition of a small quantity of ammonia. — Meconic acid and alkaline 
nieconates impart a bright red colour to ferric salts. — Alkaline indigotates 



FEMIC 15ALTS. 201 

produce the same effect (Pfiaff); so likewise does free indigotic acid. (Om.) 
Hydrosulphocjanic acid and soluble sulphocyanides impart a blood-red 
coloar to concentrated solutions of ferric salts^ and a reddish-yellow to 
dilute solutions. This colouring is produced in solutions of sesquichloride 
of iron to tho 20,000th degree of dilution. (Pfaff.) 1 part of iron in the 
form of sesquichloride dissolved in 25,000 parts of water exhibits a red 
colour; in 200,000 pts. an orange; in 800,000 a very pale orange; and in 
1,600,000, a scarcely perceptible yellow. Hydrosulphocyanic acid is 
therefore the most delicate of all testa for ferric salts. (Roth.) The 
colouring is not destroyed by hydrochloric acid unless the acid is in very 
great excess. — Ferrocyanide of potassium added to ferric salts throws 
down Prussian blue. The effect is apparent to the 100,000th degree of 
dilution (Pfaff); with 1 pt. of ferric oxide (in the form of sulphate) dis- 
solved in 420,000 pts. ot water. ^Hartig, J, pr, Chem. 22, 51.) — The pre*- 
cipitate is insoluble in hydrochloric acid.— Oxalic acid produces a yel- 
lowish colour in ferric salts, but without precipitation. — AH ferric salts 
which are not soluble in water either dissolve in hydrochloric acid or are 
decomposed by it. They are not soluble in solution of sal-ammoniaa 
(Brett.) 

^ Ferric salts are reduced to the state of ferrous or ferroso-ferrio 
Baits by many vegetable substances, e. g. fresh grass, the green branches 
of trees and shrubs, hay, wood-shavings, saw-dust, peat, and coal 
effect the reduction at ordinary temperatures; sugar, starch, gum, alcohol, 
turpentine, and shreds of paper, at a boiling heat. (Stenhouse, Ann. 
Fkarm. 51, 284.) IT. 

Ferric Acii>. FeOM 

Known only in combination with certain bases, as potash, soda, and 
baryta, with wnich it forms red salts (see these salts, especially FerraU of 
pokuh). 

Iron and Htdrggbn. 

Ferruretted Hydrogen Gas f — Hydrogen gpj3 prepared by dissolving 
iron in dilute sulphuric acid contains a small quantity of iron, which it 
deposits after a while on the sides of the containing vessel in the form of 
a brown powder. (Thomson, System of Cliemistry,) — If the gas evolved 
on dissolving iron -wire, filings, or nails in dilute hydrochloric or sulphuric 
acid, be passed through four bottles filled with potash-solution, and through 
a tube filled with asbestos, in order to retain any iron -salt mechanically 
carried over, it still retains iron and a small (quantity of phosphorus, 
although when passed through re-agents for detecting iron, it exhibits none 
of the usual characteristics. It must be regarded as hydrogen gas con- 
taining small quantities of ferruretted and phosphuretted hydrogen. — It 
has a metallic odour, likewise resembling that of garlic. When ignited 
at the orifice of a tube, it bams with a flame which is yellow at the cir- 
cumference and green in the interior, and deposits rusty brown and often 
iridescent spots on a porcelain capsule held before it; the gas prepared 
with hydrochloric acid deposits these spots more abundantly than that 
obtained with sulphuric acid. The spots disappear immediately in chlo- 
rine gas, and dissolve in nitric acid, forming a ferric salt. Strong nitric 
acid throngh which the gas has been passed for some hours, is found to 



tot nmf. 



eonUin wamM qBUitities of feme oxide and pbospborie arid. Aqveoae 
obk>rine9 iodine, wnd bromine decompose the gas, and take from it a small 
quantity of iron. From aqueous solutions of mercnrous, silver, and jUfold 
salts, tbe gas precipitates the respeciire metals. When passed throuffii a 
solution of corrosive sublimate, it throws down a white or yellowish- white 
precipitate, and afterwards bums with a pale-yellowish flame^ witbont 
depositing spots upon poroelain. — The gas obtained with English ste^- 
wire is somewhat different. Its odour is more empyreumatie, but 
metallic, and not all like garlic [probably beeaoee it contains no phos* 
phorus]. It bums with a yellow flame without any mixture of green, 
forms fewer spots on porcelain, and these SDots have more of the roetallio 
appearance of iron. The burnt odour, whieh perhaps arises from the 
presence of a hydro-carbon, is not destroyed by washing the gas with a 
eolution of corrosive sublimate or silver-nitrate. (Dupasquier, Compt. rend, 
14, 511; also N. J. Fharm. 1, 391; also /. pr, Chem. 26, 184.)—^ Ac- 
cording to Schlossberger & Fresenius {Ann, Fkarm, 51, 413), the spots 
which this so -called ferruretted hydrogen deposits on a porcelain plate 
contain not a trace of iron, but consist of certain compounds of phosphorus, 
most probably phosphoric oxide mixed with phosphoric acid ; they vola- 
til ze with tolerable facility, are insoluble in hydrochloric acid, but soluble 
in aqua-regia. Tbe gas from which these spots were obtained was puriBed 
hy passing through two wash- bottles containing distilled water, and then 
through a tube 4 feet long, half filled with moist and half with drj cotton. 
When the gas thus purified was passed throagh a solution of corrosive 
sublimate, it tlirew down a copious yellowish- white precipitate, which 
was found to contain mercury, chlorine, phosphorus, and sulphur, but 
not the smallest quantity of iron. Hence the authors conclude that the 
gas evolved by the action of dilute sulphnnc or hydrochloric acid upon 
iron is mixed with small quantities of phosphuretted and sulphuretted 
hydrogen, which produce tne reactions jost mentioned, bat is perfectly 
hee from iron, and ooAsequently that the existence of ferruretted hydrogem 
is not established, ^ 



Iron and Carbon. 

A. Carbtdb of Iron. — Iron enters into combination with carbon : 
1. In the reduction of iron-ores by excess of carbon at a heat reaching to 
the melting point : Cast-Aron, Iron-assays. 2. When iron is fused in 
contact with charcoal or diamond. A small well-closed iron crucible 
containing a diamond, and inclosed in two well-covered earthen crucibles, 
fused together with the diamond at the heat of a blast-furnace, and 
was converted into steel. (Morveau & Clouet, Scher, J. 4, 170; also Gilb, 
3, 65; Mackenzie, Sdier, J. 5, 366.) Charcoal or graphite acts upon iron 
in the same manner. — 3. Iron ignited slowly, and only to the softening 
point, in contact with carbonaceous matter, takes up carbon, which, gra- 
dually penetrating from without inwards, converts the iron, first into steel, 
and then into a compound similar to cast-iron '. — Cementation of iron, — 
If the ignition is not continued long enough to complete the process, a 
nucleus of softer iron remains in the middle — This union of iron with 
carbon takes place when the iron is surrounded with vegetable or animal 
charcoal, with coal-gas, and even with cast-iron. Iron surrounded with 
cast-iron turnings is converted into a steel at a lower red heat than when 
it is immersed in chafcoai powder. Graphite under the same eircniiK 



• 



CARBIDB OF IRON. 208 

stances does not form steel. (Gaaltier, J, Pharm, 13, 18.) An iron-wire 
immersed in melted cast-iron, which is kept at a red heat for four hours 
after solidification, is found to be converted into steel. (Degen ) 

The outermost layer of iron takes up the carbon with which it is in 
contact, transfers it to the next layer, and so on, till the carbon is disse- 
minated throughout the whole mass. In a similar manner, iron rich in 
carbon* is converted by ignition in contact with air, «. g. in the refining 
process — into wrought-iron, although the air does not come in contact 
with all the particles ; the carbon, in fact, travels from within outwards 
till equilibrium is established. (Berxelius, Jahrether, 18, 160.) — The atoms 
of iron which have combined with carbon at the surface, turn half-round, 
give up their carbon to the iron-atoms immediately within, take up 
another portion at the surface, — and so on, till the two substances have 
penetrated one another completely. At a red heat, the iron is sufficiently 
softened to allow this rotation of the atoms. (Becquerel.) Degen likewisa 
admits the probability of a galvanic movement of this kind. — Leplay & 
Laurent suppose that the carbonization of the iron is due to the action of 
r carbonic oxide gas, whii'h is produced by the ignition of the charcoal, and 
penetrates the softened metal, giving up part of its carbon to the iron, and 
being thereby converted into carbonic acid gas. At all events, they found 
that when charcoal and iron placed in two separate little porcelain boats, 
were heated to whiteness in a porcelain tube, the iron was converted into 
steel containing 0*7 per cent, of carbon ; nevertheless, they admit that 
this 'effect might be due to the carburetted hydr(»gen gas evolved from the 
charcoal, especially as no carbonization of the iron took place if the 
charcoal had been very strongly ignited before the experiment, or when 
pure carbonic oxide was passed over red-hot iron. — More recently Laurent 
has put forth the view, that the carbon volatilizes at the cementing- heat, 
and penetrates the iron in the form of vapour ; and moreover, that the 
carburetted hydrogen gas evolved from fresh wood-charcoal, and the 
cyanogen evolved from animal charcoal, may likewise contribute to the 
carbonization of the iron. (Ann, Chim. Fky9. 65, 403 and 417; also 
«/. pr. Chem, 13, 284 and 295.) The observations which Laurent adduces 
in favour of this theory, do not, however, establish the volatilization of 
carbon at so low a red-heat; and even if carbon vaponr were produced, 
the carbon would be deposited from it only on the surface of the iron, and 
could not penetrate the metal in the gaseous form : for, Laurent's 
assumption that iron when softened by ignition is permeable to gases, is 
contradicted by the fact that bubbles are produced in the interior of the 
iron during cementation — consisting of carbonic oxide gas formed in 
places where the carbon, as it penetrates the iron, comes in contact with 
scale-oxide — and these bubbles are unable to escape through the poxes of 
the iron. (Degen, Ann, Fharm, 29, 2b I.) 

According to Karsten's observations, carbon appeal rs to exist in com- 
bination with iron in three different ways : 1. Combined with the whole 
of the iron (iron completely saturated with carbon at the melting 
point appears to be Fe*C); - 2. Combined with part of the carbon, forming 
ter-carbidc of iron, FeC, which compound is diffused throughout the rest 
of the iron; — 3. In the free state, forming laminae of graphite^ — beings in 
fact, carbon free from iron, separated by slow cooling from a mass of iron 
saturated with carbon at the melting heat. — The more quickly iron com- 
bined with carbon is cooled after fusion or ignition, the greater is the 
quantity of carbca which remains combined with the whole of the iron; the 
slower the cooling, the greater is the quantity of FeC^ produced^— ^nd i( 



204 IRON. 

the iron has heen more folly Baturaied with carbon at the melting poini— 
as in the case of cast-iron — the greater is the amonnt of carbon which 
separates completely in graphite-laminae. Hence, the properties, and in 
particular^ the hardness of carburetted iron, depend not merely on the 
proportion of carbon, but more especially also, on the peculiar manner in 
which that substance is combined with it. The greater the quantity of 
carbon in combination with the whole of the iron, the harder is the 
compound, and the more completely does it resist rusting and the action 
of acids. 

The three states of the carbon in carburetted iron may be distin- 
guished by the appearances presented on treating the compound with 
acids : 

1. Carbon in combination with the whole of the iron. During the 
eolution, especially of rapidly-cooled steel and white pig-iron, an offensive 
kind of hydrogen gas containing carbon is evolved, and a volatile oil and 
a brown mouldy substance are produced. The hydrogen gas derives its 
carbon and its odour principally from the volatile oil, part of which, 
however, remains behind with the monld, and is not completely expelled 
till after long boiling with the acid. [Whether the hydrogen gas likewise 
contains carbon in another form of combination — e, g, as marsh-gas, as is 
sometimes supposed — is, in my opinion, not established by any definite 
experiment; on the other hand, according to Proust (iV'. GehX, 3,395} 1 volume 
of the gas evolved by cast-iron, although heavier than air, consumes only 
half a volume of oxygen when detonated with 2 volumes of that gas, — pro- 
bably because the oily vapour remains unbumt.] The mould forms a black- 
brown porous mass, which after washing and drying, dissolves in potash, 
forming a black-brown solution, and when heated, bums with an odour of 
peat, without leaving any ferric oxide. The formation of the oil appears 
to depend upon this circumstance, that while the iron combines with the 
oxygen of the water, part of the hydrogen, while in the nascent state 
unites with a portion or the carbon which was in combination with the 
whole of the iron, and produces the oily substance. In the formation 
of the mould, not only hydrogen from the water, but likewise a portion 
of the water itself (or its elements) appears to unite with another part of 
the carbon which was combined with the whole mass of iron, and thereby 
convert it into mould. — When nitric acid or aqua^regia is made to act on 
hardened steel or white pig-iron, no oil is formed, and instead of the 
blackrhrown mould, a red-brown substance of similar character is formed, 
which partly dissolves in the nitric acid liquid, imparting to it a brownish- 
yellow colour. This red-brown mould is probably distinguished from the 
black-brown by containing one of the oxides of nitrogen, and perhaps 
also by a larger proportion of oxygen. 

2. FeC*. When dilute sulphuric or hydrochloric acid acts upon 
slowly cooled bar-iron (which always retains a small portion of 
carbon) or on slowly cooled steel or on grey pig-iron — the action not 
being allowed to go on too long — there remains (besides the mould, which 
may be dissolved out by caustic potash), a graphite-like, but magnetic 
mass, which, if burnt alter washing and drying, leaves from 82 to 94 per 
cent, of ferric oxide, and is probably therefore FeC*. (Karsten.) 
[FeC*= 27 +18=45; consequently 100 parts of it contain 60-87 per 
cent, of iron, and these yield 8696 p. c. of ferric oxide.j Bromeis 
doubts the existence of FeC in carburetted iron; at all events, he remarks, 
when this carburetted iron is dissolved in acids, the residual graphite 

ften contains very variable quantities of iron; sometimes, however. 



BAR-nON. 205 

becaase the action of the acid has not been oontinued long enough; 
sometimes from admixture of phosphide or silicide of iron with the 
graphite. But why should the graphite, in which the presence of iron is 
stated to be merely accideutal, be converted by the continued action of 
hydrochloric acid into black-brown, and of nitric acid into red-brown 
mould ) 

3. Graphite. Remains undissolved, together with FeC, when grey 
pig-iron is dissolved in acids. — In consequence of the separation of 
mould, FeC^ and graphite, a dark spot is produced upon carburetted iron 
by the action of acids, especially of nitric acid. 

a. Bar-iroriy Refined Ir<yny MaUeahle Irony Wrcnight Iron. — All iron 
manufactured on the large scale contains a certain portion, not exceeding 
0*6 per cent, of carbon, which gives it greater solidity and thereby 
renders it better adapted for the majority of purposes, oumt Bar-iron 
is the only variety that is free from carbon. Soft bar-iron contains less 
than hard. Bar-iron is distinguished from steel, which is richer in 
carbon, by not becoming brittle or sensibly harder when rapidly cooled 
in water after ignition. 

In very dilutejhydrochloric or sulphuric acid, bar-iron dissolves very 
slowly, leaving black, magnetic, graphite-like FeC^ which is converted 
by nitric acid into brown mould, takes fire even below a red heat, and 
bums without leaving a residue.— Stronger sulptiuric acid leaves traces 
of easily inflammable charcoal. Strong hydrochloric acid dissolves bar- 
iron without leaving any residue. [Is all the carbon evolved in this case 
in the form of oil? — Cold and very dilute nitric acid forms red-brown 
mould, which dissolves on the application of heat, imparting a brown 
colour to the liquid. (Karsten.) 

Analyses of Bar-iron. According to Gay-Lussac and Wilson 
(N, Quart. J. of Sc. 7, 203; also Jahreaber. 11, 128). — a. Best bar-iron 
irom Sweden.--6. The same. — c. Bar-iron from Creusat. — d. From 
Champagne. — e. From Berry .—/. Cold-short bar-iron from Moselle. In 

100 parts: 

c. 
0159 
0-412 

trace 

trace 

Amount of Carbon in Bar-iron, a. Soft. — h. Hard. — c. d. e. Three 
different varieties, produced from white pig-iron by the Swabian method 
of refinine.— /. g. h. Three varieties produced from various kinds of pig- 
iron by the Magdesprung method of refining. The samples c to ^ are 
from the Bernbnrg works. In 100 parts: 

Kanten. Bromeis. 

a, b, e. d. e. f. g. h. 





a. 




h. 





.... 0-293 


• ••• 


0-240 


p 


... 0077 


• •■• 


trace 


Si .... 


... trace 


• ••• 


0025 


Mn .... 


trace 


•••• 


trace 



d. 




e. 


/. 


0193 


• ••• 


0-162 


.... 0144 


0-210 


•■•• 


0-177 


.... 0-510 


0*015 


•■•■ 


trace 


.... 0070 


trace 


«••• 


trace 


.... trace 



Combined 0'238 .... 0-354 .... 0-38 .... 0104 .... 0237 .... 0-66 

Free C 0-080 .... trace .... 002 .... 0*220 .... 0*260 .... trace 

Total 0-2 .... 0-5 .... 0318 .... 0354 .... 0-40 .... 0324 .... 0-497 .... 0*66 

Bromeis {Ann. Pharm. 43, 241) determined the total amount of carbon 
by burning with chromate of lead or chlorate of potash; the free, 
mechanically combined carbon or graphite was edtimated by dissolving 
the bar-iron in hydrochloric acid and determining the quantity of carbon 
contained in the insoluble residue. [Conid graphite really be obtained 



200. kllAlfi 

from bar-iron eontainiiig ao »ma11 a quantity of carbon, or did the 
insoluble residue not rather consist of Karsten's FeC ?] 

6. Steel. Preparation. — 1. Rough St^el, Refinery Steel, Natural Steely 
(Frisckdalily Rohttahl, Natiiriicher Stahl.) The iron from which rough 
steel is ma<le, is pig-iron containing but few foreign admixtures besides 
carbon and Tuanganese. It is refined by exposure to the blajst under 
charcoal, as in the refining of iron ; but the oxidation is stopped at a less 
advanced stage, so that the foreign metals, and those only, may be 
almost completely oxidized, while a portion of the carbon may remain 
nnburnt and in combination with the iron. As soon as the mass becomes 
somewhat malleable, it is formed into flnt bars under a series of hammers 
continually diminishing in size. To obtain a uniform distribution of the 
carbon, the plates, after being cut into lengths and made up into bundles, 
are welded together and then formed into ^rs: Skear-steel. {Gerbstahl,) — 
2. Bar-9teely CementcUion-tteeL Very pure bar-iron in the form of thin bars 
is enclosed in boxes, troughs or pots filled with charcoal powder, and kept at 
a red- heat for 5 to 8 days. The carbon gradually penetrates the iron ; where 
it meets with scale- oxide, it forms carbonic -oxide gas and raises the iron 
in blisters : Mistered steel. If the cementation is continued too long, the 
metal fuses together and forms cast-iron. (Buttery.) Or coal gas is 
passed over bars of iron heated to redness in a cast-iron tube coated with 
clay, whereby carbon is transferred from the gas to the metal. When a 
sufficient quantity of charcoal has entered into combination with the iron, 
the ignition is continued for some time longer, without passing any more 
gas orer the metal, in order that the carbon may diflTuse itself uniformly. 
If the gas is allowe«l to act too long, the steel fuses into cast-iron. 
(Mackintosh, J. pr. Okem. 2, 333.)— 3. Cdst-steel, Bar-steel is fused 
nnder a layer of ponnded glass, sometimes without charcoal (Buttery, 
Sckio, 35, 339), sometimes with 1 or 2 per cent, of charcoal added. In 
this process, the steel probably takes up small portions of aluminum and 
silicinm from the crucible. — 4. Iron fused at an intense heat with 2 per 
cent, of lamp-black yields good steel. (Breant, Ann, Ckim. Rhys. 24, 388; 
also iScAw. 40, 295.) — 5. The Indian Steel or WooZy vrh\ch is distinguished 
by extraordinary hardness, and by the damasked surface which it 
acquires when acted upon by acids, is said by Faraday and Stodart (Gdb. 
66, 169) to contain very small quantities of aluminum and sometimes 
also of silicium, and may be imitated by fusing the carburetied iron d 
(p. 217) with alumina, and then fusing 1 part of the carbide of iron and 
aluminum thus obtained with from 8 to 17 parts of cementation-steel. 

Properties, — Somewhat whiter than iron. When red-bot or melted 
steel is slowly cooled, it becomes soft, though somewhat harder than iron, 
and exhibits a granular, indented, and somewhat shining fracture. The 
tenacity of slowly cooled steel is to that of bar-iron nearly as 13 : 10. 
Its granular texture is not, like that of iron, converted iitto the fibrous 
by rolling and hammering. (Karsten.) The fracture of unhardened steel 
is fine-grained; that of steel which has once been re-melted perse, but not 
hardened, is still fine-grained and whiter than before. (Klsner.) On the 
contrary, when red-hot or melted steel is suddenly cooled, as by immersion 
in water — which process is called Hardening — it becomes much harder, 
more elastic, and more brittle than iron, the hardness increasing with the 
proportion of carbon. The fracture of hardened steel is more lustrous, con- 
choidal, and smooth, and of a lighter colour, but still appears fine-grained 
when examined with a magnifier. Notwithstanding its great hardness 



pTBHi. tot 

it maj be oni ibroQ^ hj ft rapidly rotating soft inm disc, because tbe 
latter l>ecoines less strongly heated. When steel is hardened after 
too strong ignition, it exhibits a coarse-grained fracture, and has bat 
little hardness or tenacity. (Karsten.) The fracture of hardened oast- 
steel is very 6ne-grained; that of cast-eteel whieh has been once re-melted 
and hardened is very dense and uniform. (Klsner, J. pr, Chem. ^0, 1 10.) 
Hardened cast-steel is harder than other kinds and takes a better polish. 

Hardened steel when heated to redness and slowly cooled, is recon- 
verted into soft steel. Hence by alternate exposure to quick and slow 
cooling after ignition » steel may be rendered either hard or soft. When 
hardened steel is raised to a temperature short of redness, it loses so 
much the more of its hardness and brittleness and approaches so much 
the more nearly to unhardened steel as the temperature is higher: 
Tempering of StetL — Accordirig to Karsten *s view, the hardness of 
rapidly cooled steel arises from the carbon which it contains being com« 
binni with the whole of the iron. When, on the contrary, the steel is 
slowly cooled) the greater portion of the carbon unites with a portion 
only of the iron and forms FeC*, which remains intimately mixed with 
iron containing less carbon and therefore soft. It is only when steel is 
very rich in carbon that a portion of that element probably separates out 
in the form of graphite, on slow cooling. 

Specific gravity of ordinary steel, 7*795; of hardened cast-steel, 
7'6578; of cast-steel not hardened, 7*9288; of cast- steel which has been 
once re-melted per se — ^in the hardened state, 7*647 — ^in the unhardened 
state, 8-0923 (£lsner); of Wooi, 7*665. (Faraday & Stodart.)— Hardened 
cast steel fuses at 2402^0.; softer cast-steel at 2531^. (Degen.) The 
heat at which steel can be welded is lower than the welding heat of bar- 
iron; the melting point of steel is also much lower than that of bar-iron, 
but higher than that of cast-iron, being, in fact, lom'er as the proportion 
of carbon is higher. Many kinds of steel cannot be welded, because 
their melting point is too close to the temperature required for welding. 
(Karsten.) Cast-steel cannot be welded with iron, because at the 
welding heat, it crumbles under the hammer, like sand; nevertheless it is 
by no means more fusible than cementation-f<teeL (Buttery.) — Steel 
acquires the magnetic power less easily than iron, but retains it much 
more btrongly. 

Atiuiunt of carbon in Steel, in 100 parts: Rough Steel 1*25. ..2*3 
(Kaisien); — softest bar-steel approaching most nearly to bar-iron, at least 
0*9 (Karsten); — harder bar-steel 1*3... 1*75 (Karsten); — white bur-steel 
from Elberfeld, 0*496 (0 416 combined, 0*80 in the form of graphite, vid. 
p. 204) (Bromeis) ;•— English bar-steel 1 87 (and 0*1 silicium) (Berthier); 
-Hsast-steel 1*65 (and ol silicium) (Berthier);-- soft English cast-steel 
0*8dd;~ordinary 1*0;— harder l-ll;^hardest 1*67 (Mushet);— best cast^ 
steel from Shettield 1*70 (0*95 combined, 0*22 free [there is an error in 
these numbers]) (Bromeis); — Rhenish cast-steel 1*267 (11 57 combined, 
0*110 free) (Bromeis) ;^ca«t-steel 28 to 30 (Karsten); oast-steel 1*758; — 
the same after being once re-melted per »e in a covered crucible 1*5776 
(Bottger & Eisner); — Hausmann's steel 1*33 (and 005 silicum) (Ber- 
thier) ; — Wooz 1 '5 (and 0*6 silicium) ( Berthier). — According to Clouet, steel 
contains, on the average, 3*1 per cent, of carbon; according to Vauquelin, 
71. In French steel, Vauquelin likewise found small quantities of sili- 
cium and phosphorus. Gay-Lussac & WiUon (N. Quart J. of 8c. 7, 204) 
found in the best English cast-steel, prepared from Swedish iron, 0*625 
per cent, carbon^ 0*03 siliciom, and a trnce of manganese; in oast-f teel from 



fc 



308 iron; 

Is^re, 0*651 p. e. carbon, with iraoeB of mlicium and manganese; in tbe 
best French cast-steel, 0.654 carbon, 0*04 siliciam, and traces of man- 
ganese; and in French cast-steel, second quality, 0*936 p. c. carbon, 0*08 
silicum, and traces of manganese. 

The smaller the quantity of carbon in steel, the more does it resemble 
hard bar-iron; the greater tbe quantity, the more nearly does it approach 
to pig-iron, — to white pig-iron in the hardened and to grey pig-iron in 
the nnhardened state. (Karsten.) IF Iron containing from 0*5 to 0*65 
per cent, of carbon may be regarded as very soft steel. As the propor- 
tion of carbon increases, the steel acquires greater hardness and tenacity. 
When the proportion of carbon is equal to 1*4 or 1*5 per cent., the limit 
appears to oe attained at which the steel, Vifter hardening, possesses the 
greatest degree of hardness and likewise of tenacity. As the amount of 
carbon increases beyond this limit, the hardness continually increases, 
but the welding power and the tenacity of the steel diminish. Steel con- 
taining 1*75 per cent, of carbon is but little adapted for welding, with 
1*9 p. c. it can scarcely be welded at all, and with 2 per cent, of carbon, 
it crumbles under the hammer at the welding heat. In this state, it 
might be regarded as cast iron; only it still retains its extensibility wnen 
cold, and has not yet acquired the property of yielding uncombined 
carbon (in the form of graphite) when very slowly cooled after fusion. 
This last effect is produced when the proportion of carbon becomes equal 
to 2 '25... 2 '3 per cent. This proportion may be regarded as fixing the 
limit between steel and cast-iron, so far as that limit can be fixed by the 
mere proportion of carbon. (Karsten, Bericktder BerL A lead. Nov. 1846; 
abstr. Ann, Pharm, 60, 229.) % 

In genuine Wooz, Faraday found 0*1304 per cent, of alumina 
(=:0'0695 p. c. aluminum), and 0*0652 silica (:=0*0316 silicinm); an« 
other sample of Indian Steel, which, when treated with acids, assumed an 
appearance quite different from that of real wooz, yielded only 0*024 
p. c. alumina (=0*13 aluminum) and no silica. 

Steel rusts less easily than bar-iron, but more easily than cast-iron. 
When heated to 215° in the air, it turns straw-yellow, then deep yellow, then 
purple, at 282^^, it assumes a violet, then a dark blue, and lastly a light blue 
colour. Since these several colours correspond to fixed temperatures, they 
are of use in determining the degree of softening produced in the tempering 
of hardened steel. Graving tools are tempered only to the light yellow, 
knives to the deep yellow or red, saws to the violet, watch-springs to the 
blue, &c. Steel shows colours at a lower temperature than iron, lower in 
fact as the steel is harder and contains more carbon. Hence, if any parts 
of a piece of iron or steel are richer in carbon than the rest, these spots 
may be known by their showing colour sooner. (Karsten.) — By repeated 
exposure to a rea-heat in contact with air, steel is converted into iron, its 
carbon being burnt away. Steel when ignited in the air does not form 
scale-oxide so readily as bar-iron; the superficial portions first give up 
their carbon, and are converted into iron, which then oxidizes. The 
nucleus, therefore, still consists of steel, outside of which is iron, and 
outermost of all, scale- oxide. The complete conversion of steel into bar- 
iron by repeated working at a red-heat takes place more quickly with 
some kinds of steel than with others. When ignited under a good coat- 
ing of welding-sand (with which the ferrous oxide produced forms a crust 
of fused ferrous silicate), steel remains unaltered. (Karsten ) — Dilute 
nitric acid placed upon steel forms a black spot, and separates a substance 
resembling graphite. Under these circumstances, the varieties (4) and (5). 



STBBL. 209 

acquire a damasked surfiioe, — ^probably because^ in addition to ordinary 
steely it contains a more highly carbonized or ainminiferous variety, which 
crystallizes in solidifying, and by continaed forging is yariously dissemi- 
nated through the rest of the steel; and this latter variety being less 
attacked by the nitric acid remains whiter than the rest. — Perfectly har- 
dened steel immersed in cold nitric acid of specific gravity 1% colours it 
brown-red, with a slight evolution of nitric oxide gas, and gradual sepa- 
ration of black, metallic-shining, non-magnetic flakes, which burn without 
leaving any residue of ferric oxide, dissolve in caustic potash forming a 
black-brown solution, and by continued action of the acid are converted 
into a brown-red powder. If the acid is heated, the same effects are pro- 
duced, but more quickly and with considerable frothing. (Karsten.)— 
Steel which has not been hardened dissolves very rapidly in strong nitric 
acid, imparting to it a brown-red colour, due to dissolved mould, part of 
which substance, however, remains undissolved in the form of a brown-red 
powder. Previously to the formation of this mould, graphite-like laminso 
(probably consisting of FeC) are separated, and these when burnt leave 
from 82 to 94 per cent, of ferric oxide (vid. p. 205). When steel which 
has been slowly cooled is treated in this manner, the laminsB are converted 
into red-brown mould, at the very moment of separation. — Soft cementa- 
tion-steel dissolves very slowly in dilute nitric acid, yielding no graphite- 
like laminae, but only red-brown mould, which takes fire even below a red- 
heat. Cast-steel dissolves still more slowly. (Karsten.) — Dilute sul- 
phuric or hydrochloric acid dissolves steel, with evolution of fetid hydrogen 
E containing an oily vapour, and separation of a graphite-like substance 
obably FeC'] which, by continued action of the acid, is converted into 
ck-brown mould. — Hardened steel immersed in dilute sulphuric acid 
becomes covered with a small quantity of a black metallic powder; un- 
hardened steel, in the same time, with eight times as much of a grey powder, 
which is soft, coherent, and may be cut with a knife, and appears to 
consist of carbide of iron, — inasmuch as, when exposed to the air, it 
changes colour in consequence of the iron becoming oxidated. Bj con- 
tinued boiling with the acid, it is converted into a black powder [mould] 
the same as that produced by hardened steel. This substance, when 
heated in the air to temperatures between 1 50° and 200"", burns like 
a pyrophorus, emitting a large quantity of smoke ; at higher tempera- 
tures it bums like asphaltum, with a bright flame, leaving a residue of 
ferroso-ferrio oxide; it is likewise completely soluble in boiling nitric 
acid. (Fanulay & Stodart, GUb. 72, 256.) — Thoroughly hardened steel 
dissolves very slowly in dilute sulphuric or hydrochloric acid, becoming 
covered in the course of a few days, with black-brown mould, which is 
converted by nitric acid into brown-red mould. Stronger sulphuric acid 
when moderately heated also leaves a residue of black-brown mould, but 
boiling concentrated sulphuric acid dissolves the steel completely. (Kar- 
sten.) [Does the whole of the carbon in this last case go off in the 
form of oil or of gaseous carburetted hydrogen 1] — ^Un hardened steel 
exhibits with dilute sulphuric or hydrochloric acid the same effects as 
wrought iron; excepting that it dissolves much more slowly, and leaves 
a more abundant graphite-like residue. [FeC] Stronger sulphuric 
acid dissolves soft steel with tolerable rapidity, causing a separation of 
shining laminae (FeC) which are afterwards converted into black-brown 
mould. (Karsten.) If the acid be quickly poured off, before this conver- 
sion has proceeded to any considerable extent, and the mould already 
formed be extracted with caustic potash^ magnetic laminsa are left, 
VOL. y. r 



210 IRON. 

which retain their metallic aspect under water, bat lose it in the air, q.Qd 
are quickly converted into mould by the action of acids. (Karsten.) 

Steel may be ma<le to unite with several metals by fusion. Many of 
these metals united with it in very small quantity, render it harder and 
more brittle. If the other metal is more electro -negative than the steel, 
and partly separates out in fine particles as the metal cools, the steel is 
thereby rendered more liable to rust. Moreover, all these alloys — ^parti- 
cularly those which do not contain too much platinum — disengage a 
larger quantity of hydrogen from dilute sulphuric acid in a given time 
than pure steel, doubtless because a portion of the more electro-negative 
metal is laid bare by the first action of the acid, and then accelerates the 
solution of the iron by galvanic action. Pure steel dissolves most slowly 
of all in sulphuric acid; then follows that which is alloyed with small 
quantities of chromium; then with silver; then with gold; then with 
nickel; then with rhodium, iridium, or osmium; then with palladium; 
and lastly with platinum. The alloy of steel and platinum gives with 
sulphuric acid, in a given time, 100 times as much hydrogen gas as pure 
steel; even ^^ platinum is sufficient to produce this effect, but with 

^-J^ Y^ the action is still stronger. (Faraday &Stodart, PhiL Trans. 

1822, 253; also Crilh. 72, 225.) — The greater hardness which steel 
acquires by fusion with these metals appears to result, not so much from 
their presence as from the additional fusion to which the steel must be 
subjected to form the alloy; at all events, silver-steel exhibits no greater 
hardness than steel which has been re-melted per se, vid. silver, (Eisner, 
J, pr. Chem. 20, 110.) Iron free from carbon may indeed be rendered 
harder by combination with phosphorus, sulphur, arsenic, &c., but such 
compounds do not harden by sudden cooling, or at all events but slightly. 
(Karsten.) 

c. Ordinary Pig-iron; Cast-iron, — Obtained by the reduction of 
native iron-oxides by means of charcoal or coke m the blast-furnace 
(p. 166). It contains more carbon than steel, and is besides contami- 
nated with various substances, particularly phosphorus, sulphur, arsenic, 
manganese, molybdenum, vanadium, chromium, copper, calcium, mag- 
nesium, aluminum, and silicium. 

The properties of this substance vary according to the nature and the 
proportion of the substances combined with the iron, and likewise accord- 
ing to the rapidity of cooling from the state of fusion. For the most 
f>art, cast-iron exhibits a laminar or granular texture, sometimes crystal- 
izes in octohedrons, and is more brittle, specifically lighter, and more 
fusible than malleable iron. At a red-heat, it is so soft that it may be cut 
with a saw. 

Melted cast-iron, whether white or grey, yields white cajst-iron by 
sudden cooling and grey by slow cooling. The former corresponds to 
hardened, the latter to unhardened steel, excepting that the steel contains 
less carbon. After sudden cooling, the carbon remains combined with the 
whole of the iron; but if the cooling be slow, the carbon has time to 
separate for the most part from its state of combination with the whole 
of the iron, partly as graphite, partly as FeC. (Karsten.) Part of the 
graphite remains diffused through the iron in scales; the rest crystallizes 
out. The greater the quantity of carbon in white cast-iron, the more 
strongly must it be heated in fusing and the more slowly must it be 
coolea after fusion, in order to convert it into the grey variety. On the 
other hand, grey cast-iron is most easily converted into white, by heating 
^ *'i6t to the melting point [because tnen the cooling takes place more 



CAST-IltON. %llt 

rapidly throughout the whole maaa]. In iron oafitings, those parts of the 
iron which have been in direct contact with the mould are of the white 
Tariety, being lighter iu colour as the mould is wetter and the casting 
thinner; in the interior of the mass, the white iron passes imperceptibly 
into the grey. When fused cast-iron very rich in carbon is ruu into a 
Tery wide open mould, and thrown into water as soon as it has become 
8obd on the surface, the portion which still remains fluid in the interior 
is converted by the rapid cooling into white iron. (Karsten.) 

Although we must admit, with Karsten, that the different rate of 
cooling is the principal circumstance which determines the production of 
white or of grey cast-iron, we can nevertheless scarcely follow him in 
regarding it as the only cause of the difference; for the varying quantity 
of the other elements contained in it appears likewise to exert an influ* 
ence on the result. Why is it that white and grey iron sometimes occur, 
and with sharp demarcation, in the same piece of iron ? (infra.) Why 
is blackish-grey pig-iron so difficult to convert into white 9 Why does 
the same furnace, according to the manner iu which it works, yield at 
the same rate of cooling, sometimes a whiter, sometimes a greyer iron 1 
Why does fused grey pig-iron solidify in the form of white bright iron 
on the addition of sulphur (infra); and if the bright iron be distin- 
guished merely by containing the greatest quantity of carbon, why is it 
not obtained by fusing pure iron with excess of charcoal ? (Gm.) 

Varieties of Cast or Pig^rqn, particularly according to Karsten: 

A. WTiite Pig-iron, — Varies from tin-white to greyish-white; very 
brittle, cracking easily even by change of temperature; extremely hard, 
sometimes even more so than hardened steel, so that it will resist the 
strongest file; scratches glass easily. Fracture, sometimes laminar, 
sometimes lamino-radiating, sometimes finely splintered, sometimes dense 
and conchoidal. As the fracture changes from laminar to conchoidal, the 
colour likewise varies from white to greyish. Mean specific gravity, 7-5. 
Expands less than grey cast-iron when heated. Cannot be welded, 
because it becomes pasty at the very lowest welding heat. Puses less 
readily than grey pig-iron. When heated to the melting point, it does 
not suddenly pass into the fused state, like grey pig-iron, but is converted 
before fusing, into a soft, pasty mass. In this variety of pig-iron, the 
carbon is united with the whole of the iron. Continued ignition out of 
contact of air, does not alter bright iron, bat imparts a grey colour to 
those kinds of white pig-iron which are less rich in carbon, and renders 
them less hard and brittle. (Karsten.) 

a. Bright 7ron, Bough Steel-iron (Spiegeleisen, Spiegeljtoss, Bohstahleisen. 
RoJistaklflosSy HaHfloss), Tliis is the hardest of all kinds of iron; it 
resists the strongest file; exhibits a coarsely laminar fracture, with silver- 
white, specular, fractured surfaces. The most fusible of all kinds of pig- 
iron. Especially rich in carbon. 

h. Whitish-grey Pig-iron. 

c. Flowery Pig-iron {Blumiges Poheisen, llumige Flossen), Bluish, 
with a radiating, highly lustrous fracture. 

d. Greyish-white Iron, having a fracture without distinct structure. 

e. Porous Pig-iron {luckiger Poheisen, Itiekiger Floss, WeieMoss). 
Less white, with a bluish or greyish tinge with a somewhat indented 

racture; porous Forms the transition to grey pig-iron and to steel. 

B. Grey Pig-iron. — Between light grey and black. Sometimes with 

p2 



212 IRON. 

a strong lustre; sometimes, when it contains considerable quantities of 
foreign metals, especially silicium, it is dull. Fractare granular. If the 
grains become flat and scaly, the iron is impure. Innumerable scales of 
graphite are interspersed between the particles. The grains, which 
resemble those of unhardened steel, consist principally of the compound 
of carbon with the whole of the iron; FeC may, however, be mixed with 
them. Mean density 7*1. More or less soft and extensible, possessing 
these properties in a greater degree when cold than at a red heat. This 
kind of cast-iron would be very malleable, if it were not mixed with 
graphite. It may be welded, though not easily, because the welding 
and melting points are very close together. The more carbon it contains 
the more readily does it fuse, and with an equal proportion of carbon, it 
is less fusible than white pig-iron. Some varieties of it are as refractory 
Ibs the harder kinds of cast-steel, others fuse almost as easily as bright 
iron. (Karsten.) A sample of pig-iron examined by Degen fused at 
1326° C. Its passage from the solid to the liquid state takes place 
almost instantaneously, the melting point be ins nigher and the fusion 
more sudden as the proportion of carbon is smaUer. When very slowly 
cooled after fusion, it becomes more malleable than before; by sudden 
cooling it is converted into white pig-iron, the conversion bemg more 
complete as the proportion of carbon is greater. Thus white iron is 
obtained by pouring water on the iron which has been run off into the 
grooves and taking out the crusts of solid metal thus produced. The 
blackish-grey iron obtained when the furnace is working very hot, is 
however dimcult to convert into white iron; but complete conversion 
may be obtained by pouring it into water in a fine stream. (Karsten.) 
[Is not the blackish-grey pig-iron peculiarly rich in carbon 9] It is not 
altered by continued ignition with charcoal out of contact of air. It 
hardens by cooling in water after ignition. (Karsten.) When hardened, 
it scratches glass and resists an English file. (Bromeis.) 

a. Mottled or Mixed Pig-iron (UdLhirtea Eoheisen, gefieckten Roheisen), 
A mixture of white and grey iron. In strongly mottled iron, little stars 
and spots of grey iron are found interspersed in bright or flowery iron; 
weakly mottled iron, exhibits white specks on a grey ground. In streaked 
iron {spenglickes or streifiges Eiten) grey iron is found above and below, 
and bright iron in the middle, with strong demarcations. 

h. Grey, Normal Pig-iron {Graues, gares Roheisen). Produced when 
the charcoal, ore, flux, and air in the blast-furnace are in normal propor- 
tion. The slag or cinder produced under such conditions is perfectly 
fused, contains very little iron, is free from graphite-laminse, sometimes 
vitreous and of a greenish or blue colour, sometimes crystallo-granular, 
laminar, and greyish-white. Normal cast-iron is of small-grained struc- 
ture, and interspersed only with small graphite-lamina); possesses great 
tenacity; is easily filed, turned, and bored; may even be hammered to a 
certain extent; does not readily crack from change of temperature; and 
is best adapted for most kinds of casting. 

c. Blacky supernormal Pig-iron {Sckwarzes, uhergares Roheisen), Pro- 
duced when the blast-furnace is very hot and the supply of coke or 
charcoal too great. Tbe grey, fine-grained mass then produced is 
abundantly intersected and superficially marked with laminae of graphite, 
whereby its solidity is diminished. 

Analyses of Cast or Pig-iron. — 1. Smelted with charcoal, a. From 
Belabre;— (• from Autray;-^<r. from Bese;— o?. from St. Diiier; — e. from 



CAST-IBON 213 

Sweden;-^, from Tredion; — ^. from Lohe.— 2. Smelted with coke:— A. from 
Firmy; — L from Janon;--^. from Charleroy;-^. from England;— ^m. Fine 
metal from Firmj (t. e, iron from Firmj melted a second lime). All the 
proportions are given in 100 parts. (Berthier, Ann, d. Min. 1838; abstr. 
Jahresber. 14, 127.) 

a. b, e. d. e. /. ff. A.'' 

C .... 2*95 .... 3*5 .... 3*05 .... 3'6 .... 4*2 .... 3*6 .... 3*50 .... 3*0 
Si .... 0*28 .... 0.3 .... 0-07 .... 0*4 .... 0*5 .... 0*5 .... 0*45 .... 4*5 

i. t, U m. 

C 4*3 .... 2*3 .... 2*2 .... 1*7 — 1*00 

Si 3*5 .... 3*5 .... 2*5 .... 0*5 — 0*15 

Iron smelted with coke is therefore much richer in silicinm than that 
which has been reduced by charcoal. 

a. Pig-iron from the Royal Works iu the Harz^ smelted with cold air; 
of sp. gr. 7*43; mottled.—^. The same^ smelted with air at 250^; sp. gr. 
7*160; normal and of a grey colour. — e. Pig-iron from Leerbach in the 
Harz; cold blast; sp. gr. 7*081; very grey.— ^. The same, smelted with 
air at 110°; sp. gr. 7*077; very grey. The hotter the blast, the greater 
is the quantity of silicinm which unites with the iron; the proportion of 
phosphorus, on the contrary, remains the same. (Bodemann, Pogg, 
55, 485.) — e. Grey, soft pig-iron from the Maximilian Works at Bergen. 
(Fuchs, J. pr. Ckem, 17, 166.)—/. Good pig-iron free from manganese, 
from the Leke iron-works. (Berzelius, Scher. Ann. 7, 22 1 .) 

a, b. Cm d» €, f, 

Fc 93*29 .... 91*42 .... 93*66 .... 91*98 .... 94*33 .... 91*16 

p /combined 2*78 .... 1*44 .... 0*48 .... 0*951 • ., -.^^ 

^ Ifree 1^99 .... 2*71 .... 385 .... 3*48/ — ^ ^^ " ^ ^" 

P 1*23 .... 1-22 .... 1-22 .... 1-68 .... 0-37 

8 trace .... trace .... trace .... trace .... 0*12 

Ca trace .... trace .... .... .... M^ 0*12 

Al .... .... trace .... trace 

Si 0*71 .... 3*21 .... 0*79 .... 1*91 .... 1*75 .... 0*25 

Mn trace .... trace .... trace .... trace .... .... 4*57 

Cr and Y — trace 

10000 .... 10000 .... 10000 .... 10000 .... 100*00 .... 10000 

a. a. Grey pig-iron from Wales, smelted with coke, No. 1;— 5. No. 2; 
c. No. 3; — d. Grey pig-iron from Franche-Comte, smelted with coke; 
0. The same from Ureusat;— /. The same from the Champagne; — g. Grey 
pig-iron, with coke and wood, from Berry; — K Grey pig-iron, with char- 
coal, from Nivemais; — i. White pig-iron, with wood, from the Champagne; 
' ~' I The 



h. The same, from the Is^re; — I, The same, from Siegen; — m. The same, 
from Coblenz. The quantity required to make up the hundred parts is 

iron. (Gay-Lussac & Wilson, N. Quart. J. of Sc. 7, 204; also Jahresher. 
11, 128.) 

a. b. e. d. f. /". 

2-45 .... 2*55 ... 1*67 .... 2*80 .... 2*02 .... 2-10 

P 0-78 .... 0-44 .... 0-49 .... 0*35 .... 0*60 .... 0*87 

Si 1*62 .... 1*20 .... 300 .... 1*16 .... 3*49 .... 1*06 

Mn trace .... trace .... trace .... trace .... trace .... trace 

C 2-32 .... 2-254 .... 2*324 .... 2*636 .... 2*69 .... 2*4*4 

P 0*19 .... 1043 .... 0*703 .... 0*280 •.. 016 ... 019 

Si 1*92 .... 1*030 .... 0*840 .... 0*260 .... 023 .... 0*23 

Mn tnue .... trace .... trace .... 2*)40 ... 2*59 .... ?'4^ 



214 IRON. 

In tiie following investigations, only the proportion of carbon in the 
pig-iron was determined; a. Grey pig-iron from Sain, reduced from 
Brown Iron-ore with charcoal. — b. The same, from Widdenstein in 
Biegen, reduced from Brown Iron-ore and Spathic Iron-ore by charcoal; 
c. The same from Malapan in Silesia, reduced from Sphierosiderite by 
charcoal. — d. The same from the Royal Works in Silesia, obtained from 
Ochery Brown Iron-ore by coke. — e. The same, but with a less hot 
working of the furnace. (Karsten, Schw, 68, 182.) — Pig-iron from the 
Bernberg: a. Grey; — b. Ordinary white; — c. Very light white; — d. White, 
and of norma] ooraposition; — e. Perfectly bright or specular iron containing 
7 per cent, of manganese. (Bromeis, Ann, Fharm. 43, 241.) All the 
numbers refer to 100 parts. 

Karsten. 

M, 0« ^4 d» t, 

ComMned Carbon .... 0'89 .... 103 .... 075 .... 0*58 .... 095 
Free Carbon 3 71 .... 362 .... 315 .... 257 .... 270 

ToUl 4-60 ..,. 4'66 ...! 390 .... 316 ... 3-65 

Bromeis. 



0. 9. C a. ۥ 



Combined Carbon ...« 0*93 .... 1*514 .... 2-518 .... 2*908 .... 3*10 
Free Carbon 2*34 .... 1*040 .... 0500 .... 0*550 .... 072 

Total 327 .... 2*554 .... 3*018 .... 3*458 .... 3*82 

Bright iron contains the largest proportion of carbon, viz. 5*3 per 
cent=:Fe*C. [This is contradicted by the above analysis of Bromeis.] 
This quantity of carbon is not increased by fusion in a crucible lined 
with charcoal. With 4*25 per cent, of carbon, the laminar texture is 
still distinct ; with a smaller quantity of carbon, it passes into the ra- 
diated; with a still smaller quantity, it exhibits a close and then a 
granular fracture, the whiteness at the same time diminishing; but 
when the proportion of carbon is still further diminished, the grey colour 
becomes lighter again. Porous cast-iron contains 3*5 per cent, carbon. 
(Karsten.) 

The substances which occur in pig-iron in addition to the carbon, 
probably form compounds with a portion of the iron, which are finely 
diffused through or dissolved in. the carbide of iron. These admixtures 
affect the quality of the iron as follows : — 

Phosphorus imparts to iron the property of fusing tranquilly, and 
forming a thin liquid; and since phosphide of iron solidifies less quickly 
than pure iron, it is well adapted for castings; but if the proportion of 
phosphorus amounts to 1*5 per cent., the iron loses its solidity. The 
largest proportion of phosphorus, as it occurs in iron from Limonite^ 
amounts to 5'6 percent. (Karsten.) % Schafhautl (J, pr. Chem, 40, 304) 
remarks that cast-iron, bar-iron, and steel almost always contain more or 
less arsenic and phosphorus, which often greatly improve their quality. 
Thus the celebrated Dannemora iron and the English Low-Moor iron 
owe their good qualities to the presence of arsenic ; and a particular kind 
of Bus^ian iron (marked CCND) from Demidorff's works at Nischnetag- 
ilsk is indebted for its peculiar qualities to the phosphorus which it 
contains. ^ 

Iron which contains sulphur becomes viscid and solidifies quickly, if 
cooled in the least degree after fusion, and during the solidification^ 



CA8T-IH0N. 215 

^sarities and air-bubbles are often formed. Even if the quantity of 
enlphur amounts to only 37 per cent., the metal when converted into 
bar-iron is perfectly useless, breaking to pieces under the hammer at a 
red heat. — When a small quantity of sulphur (^ to ^) is stirred about at 
the bottom of melted grey pig-iron prepared from manganiferous brown 
iron-stone, the fused mass solidifies in the form of bright iron, exactly 
resembling that from which rough steel is prepared. Pig-iron free from 
manganese likewise, when thus treated, yi^ds bright iron, containing : 
Fe 9 4 '03, — combined carbon 4*93 (it does not contain graphite), — S 0*61, 
— ^i 1*05 (exoeas 0-62.) Even if this process does not produce bri^t or 
specular iron, it at least always yields white iron. On the other band, fused 
bright iron obtained from spathic iron-ore is, by admixture of sulphur, 
completely converted into grey pig-iron. In all these fusions with sul- 
phur, a black mass consisting of graphite and sulphide of iron separates 
on the surface of the metal. [Consequently, the sulphur expels a portion 
of the carbon from its combination with the iron.] (Huene, «/. pr. Ghent, 
26, 308.) 

Siiicium becomes mixed with the iron in considerable quantity when 
ooke is nsed as the reducing agent; the largest amount found by Karsten 
was 3 '46 per cent. A larger proportion deprives grey oast-iron of its 
lustre, and gives it a dull aspect and an ash-grey colour; a similar 
effect is produced by other eartk-metaU. Generally speaking, grey cast- 
iron contains more siiicium and manganese than the white variety. 
(Karsten.) 

Arsenic occurs in pig-iron more frequently than is commonly sup- 
posed. It is not evolved in the form of arseniuretted hydrogen gas when 
ihe iron is dissolved in dilute sulphuric acid, but remains in the black 
residue, horn which it may easily be extracted by caustic potash or hydro- 
sulphate of ammonia, and then precipitated by acids in the form of sul- 
phide of arsenic, or, in the case of the potash-solution, by passing 
sulphuretted hydrogen through the liquid, and boiling. This sulphide of 
arsenic often leaves a small quantity of sulphide of molybdenum when 
distilled. (Wohler, Ann. Fkarm, 31, 95.) 

Sefstrom reduced ferric oxide mixed with various foreign substances, in a 
charcoal crucible before the blowpipe, whereby different elements, such 
as phosphorus, sulphur, arsenic, siiicium, calcium, magnesium, aluminum, 
and manganese were made to combine with the iron, and alter its pro- 
perties. (For the results of these important experiments, vid. J. techn. 
(?hem. 10, 145.) 

Cast-iron, when heated in the air, exhibits the same surface-colours as 
steel and bar-iron. White iron shows colour sooner than steel; cast- 
iron sometimes more slowly than bar- iron. (Karsten.) Cast-iron, by con- 
tinued ignition in the air, is converted from without inwards into scale- 
oxide, the carbon at the same time escaping. — If the ignition be interrupted 
before the white cast-iron is completely converted into scale- oxide, the 
remaining iron, from loss of carbon, is found to be dark-grey, soft and mal- 
leable like the softest grey cast-iron, but does not appear brittle or porous. 
If it be protected from the air during ignition by covering it with various 
powders, even with charcoal powder, it is converted into the same kind 
of soft cast-iron, without much formation of scale-oxide. The same 
conversion takes place without any formation of oxide, when white cast- 
iron is surrounded with chalk, ashes, or ferric oxide, and ignited in close 
reesels. On this property depends the annealing of iron castings.— Grey 
cast-iron when exposed to the air corers itself with scale-oxide, and at 



216 IRON. 

the same time becomes more and more brittle till it is completely 
oxidized. It likewise passes into a brittle, porous state^ when heated 
to redness nnder chalky ferric oxide, &c. — If white cast-iron is heated in 
the air till it becomes soft and pastj, it gives up its carbon more qaickly 
than when merely heated to redness, and ultimately passes from the steel* 
like state to that of pure iron, without the great loss of iron which is nn- 
avoidable when the metal is completely fused. Since, however, when the 
amount of carbon is considerable, the pasty condition quickly passes 
into the liquid state, this mode of remoring the carbon cannot be applied 
to bright iron, which is very rich in that element. — White or grey cast- 
iron, when fused in the air, becomes covered with scale-oxide, and if this 
be constantly removed, the whole of the metal is quickly oxidized; if, 
however, the oxide be left on the sur&ce, it increases but slowly, and the 
iron becomes more free from carbon, more like steel, and difficult to fuse. 
— Grey cast-iron fused under a layer of carbonate of potash, soda, lime, 
or magnesia, the temperature being raised as the metal becomes more 
refractory, is converted into perfectly malleable steel-like iron. It 
cannot, however, be completely deprived of carbon by this process; 
neither does it take up any alxali-metal. The carbonic acid in the 
carbonates is doubtless converted into carbonic oxide. (Karsten.) 

Nitric acid forms a black spot upon cast-iron, dissolves it with eye* 
lution of nitrous gas and carbonic acid, and leaves a brown, soft, mouldy 
residue. This latter substance smells like peat when heated, and glows 
when set on fire, emitting the same odour and leaving a greyish-red ash. 
Many kinds of this mouldy substance are slightly soluble in water, others 
more abundantly, especially in hot water, from which they separate 
partly by cooling, partly by evaporation; but all varieties of it dissolve 
easily in ammonia and potash, forming a black-brown solution, from 
which acids throw down a precipitate. (Berzelius, Scher. Ann. 7, 224.) 
If cast-iron be immersed in water, and nitric acid free from nitrous and 
hydrochloric acid be gradually added so that the temperature may not 
nse above 50^, there remains a black -brown mould, which, when heated 
in the air, emits fumes of a peculiar but not exactly empyreumatie 
odour, and then bums away with a glimmering light; when subjected to 
destructive distillation, it leaves a rescue of <3iarcoal, and yields a dis- 
tillate of ammonia, together with an empyreumatie oil which smells like 
tobacco. (Berzelius, Fogg. 27, 126.) — Cold nitric acid of specific gravity 
1 *d gradually dissolves white cast-iron, with separation of black flakes^ 
which if left immersed in the acid, slowly acquire a brown-red colour; 
boiling nitric acid or aqua-regia acts in the same manner, but more 
quickly and with great frothing. — On grey cast-iron, cold nitric acid acts 
but slowly; the softer kinds are afiected by the acid in the same manner 
as soft steel — the harder and lighter varieties {e. g. the mottled), like 
hard steel. After a time the action ceases altogether, but be^ns again if 
the graphite-lam insB are separated from the iron. Nitric acid is coloured 
h}the mould which it dissolves. Aqua-regia acts in the same manner as 
nitric acid. (Karsten.) 

Dilute sulphuric or hydrochloric acid also dissolves cast-iron — the 
grey more easily than the white— with evolution of hydrogen gas, conta* 
minated with the vapour of a disagreeably-smelling oil, sometimes also 
containing sulphur and phosphorus, and perhaps mixed with marsh-gas; 
a carbonaceous residue is left, exhibiting three varieties of composition 
and properties. If the hydrogen gas, as it is evolved, is passed through 
alcohol, that liquid takes up the oil (first observed by Proust [Scher, J. 



\ 



CAST-IRON. 217 

9, 480; also GUb. 24, 293]), which may then be fleparated from it bj 
adding water. When cast-iron is dissolved in hydrochloric acid, more 
hydrogen and less oil are obtained than when sulpharic acid is used; 
Mrt of the oil remains in the carbonaceous residue, and may be extracted 
by alcohol. (Beraelius.) Oil of vitriol through which the hydrogen is 
passed, completely absorbs the yaponr of the oil, acquiring a yellow and 
afterwards a deep-red colour. (Scfarbtter, Ann. Pkarm. 39, 302.) — ^When 
cast-iron is dissolved in hydrochloric acid, there remains a brownish 
residue, which turns light yellow on drying, and when burnt becomes 
black, and leaves a residue of silica. Sulphuric acid leaves a black and 
more copious residue, which also leaves silica when burnt. (Berzelius.) 
— White cast-iron is almost insoluble in dilute sulphuric or hydrochloric 
acid; when immersed for some weeks in either of these acids, it becomes 
covered with a black dust or moul^. Stronger sulphuric acid at a boiling 
heat dissolves white iron, leavinfi^ a residue of blad^ carbonaceous matter 
having a metallic aspect [mould 9]; boiling concentrated hydrochloric 
acid dissolves white iron completely. — Grey cast-iron dissolves very 
slowly in dilute sulphuric or hydrochloric acid, and after a few months, 
leaves a residue consisting of three different substances : 1. Graphite, in 
non-magnetic scales, which have a metallic lustre, are insoluble in acids 
and alkalis, and bum without residue. 2. A magnetic, graphite-like 
mass (FeC) which becomes heated when dried in the air, and is in 
other respects similar to that which is obtained by the same process from 
nnhardened steel (p. 210). 3. Black-brown, non-magnetic mould, which 
boms away below a red heat^ and dissolves in caustic potash, form- 
ing a black-brown solution. Graphite is never absent from the residue; 
but it is mixed, sometimes with the graphite-like matter, sometimes with 
mould. When grey cast-iron is dissolved in strong sulphuric acid, the 
xesidue consists of graphite, and black, easily inflammable mould; hot 
concentrated hydrochloric acid dissolves grey iron quickly, leaving a 
residue of graphite. — ^White cast-iron which has been rendered srey and soft 
by continued ignition, comports itself with nitric, sulphuric, and hydrochloric 
acid in the same manner as unhardened steel which has been rendered 
denser by hammering. (Karsten.) — IT Acccordin? to Landrock {Arch, 
Pkarm [21, 54, 1), the insoluble residue left by the action of dilute sul- 
phuric acid on cast-iron does not in any way partake of the nature of an 
organic substance; and that which is dissolved out of it by potash is not 
a substance resembling mould or humus, but consists mainly of ferric 
oxide and silica, the ferric oxide being rendered soluble in potash through 
the medium of the silica; the volatile products resulting from the action 
of the acid are hydrogen, arseniuretted, phosphu retted, and sulphuretted 
hydrogen, and sulphurous acid IT. — When the residue obtained on dis- 
solving grey cast-iron in hydrochloric acid is treated with ammonia, it 
rapidly gives off hydrogen, together with traces of marsh-gas, and yields 
alumina (so far as all kinds of cast-iron contain aluminum) and silica to 
the ammonia. The residue left on dissolving white iron in hydrochloric 
acid, does not effervesce with ammonia, provided no grey-iron was mixed 
with the white. (Schafhautl, hrieflicks MUtheilung,) IT According to 
Hull (Ann Pharm. 74, 112), the evolution of hydrogen in the manner 
just mentioned is purely a mechanical phenomenon. The hydrogen is, 
in fact, mechanically inclosed in the porous carbonaceous residue, and is 
evolved from it, not only by contact with ammonia, but likewise by boil- 
ing with pure water. Its liberation by ammonia at ordinary tempe- 
ratures, probably arisee from this cironmstance, that the ammonia dis* 



216 IROH. 

tolyes tbe oily ky^booarbon oontatned in the carbotuioeoiui reaidie, therBby 
wetting and peneUntiog it completely IT. 

Daniell {Sckw. 19, 202) by dissolving oast-iron in hydrochloric or 
sulphuric aoid, obtained a substance which could be cut with the knife, 
and when dried in the air upon blotting-paper, became heated, and, if 
in mass, even took fire spontaneously. — Cannon-balls (not all) which had 
lain for 42 years under sea-water, were found to be converted into a 
substance like plumbi^, some to the thickness of half an inch, others to 
the very centre. (Sillman, Sill, Amer, J. 4, 178; also Sckw. 35, 481.) 
[The balls which withstood the action of the sea- water probably consisted 
of white cast-iron.]— Cannon-balls lying in the sea on the coast of Nor- 
mandy, where they had been deposited during a sea-fight in 1692, had 
retained their form and bulk, but lost two-thirds of their weight; they 
yielded to the knife, had no action on the magnet, and no longer con- 
tained metallic iron. (Deslongchamps, J, Chin^ Jf^d, 13, 89.) Balls 
raised at Carlscrona from a ship sunk 50 years before, were found to foe 
converted, through one-third of their mass, into a porous, graphitic sub- 
stance, which became strongly heated when exposed to the air for a 
quarter of an hour, so that the adhering water evaporated* (Berseliua, 
Lekrb.) — ^Sea-water does not extract all the iron from cast-iron, but, like 
dilate sulphuric acid, leaves graphite mixed with a graphitic substance 
(FeC^) which, as it dries in the air, becomee heated even to redness. 
Cast-iron immersed in f^sh-water is likewise oonverted by the carbonic 
acid of the air — though very slowly and with deposition of iron-rust — into 
the same mixturo of graphite and FeC (Karsten.) Oxidation of cast- 
iron— -even more rapid than in sea-water — likewise takes places at the 
mouths of rivers falling into the sea, where, at the ebb and flow of the 
tide, the lower part of the iron is placed in contact with sea-water, and 
the upper part with river- water, so that a galvanic [Bucholzian] cirouit 
is formed. Foul sea-water acts moro strongly, in consequence pf the 
hydrosulphuric acid which it contains. The surface of the iron, which, 
by the sadden cooling in moist sand, has been brought to a state approach- 
ing moro nearly to that of white cast-iron — ^resists the action of the water 
better than the interior. (Mallet, J. pr. Gkem, 22, 352.) — Aqueous chlo- 
ride of copper extracts all the iron from cast-iron, leaving behind the whole 
of the carbon mixed with copper. (Berzelius, Pogg* 46, 42.) — A similar 
action is produced when cast-iron is placed in contact with a lump of fused 
chloride of silver under water containing a few drops of hydrochloric 
acid. The silver is thereby reduced. (Berzelius.) — The harder kinds of 
white cast-iron placed in contact with water and chloride of silver aro 
slowly decomposed, leaving a black-brown mould; the softer kinds de- 
compose more quickly and leave graphite, black-brown mould, and the 
graphitic mass FeC, which, by longer action of the chloride of silver, is 
likewise converted into black-brown mould, though lees quickly than in 
dilute acids. Grey cast-iron gives with water and chloride of silver a 
mixturo of graphite and FeC (Karsten.) — Aqueous solution of iodine 
acts in the same manner as the metaUic chlorides. (Berzelius.) 

White or grey cast-iron immersed in charcoal powder and ignited for 
a long time, or fused, takes up from I to 1|- per cent, moro carbon, 
unless it is proviously saturated with carbon like bright iron, and the 
white variety, when heated to redness between charcoal, becomes groy and 
soft. (Karsten.) 

[rpon bar-iron, steel, and cast-iron, see especially Karsten {System der MetaU 
Iwrgie, 1831-32, Bd. 4; also Schw, 66« 51 and 166). Hie namenros experiments of 



FERROUS CAEBONATE. ^£19 

SchAfliftaa (/• pr, dm. 19, 150 and 408 1 20, 465 < 21, 129) in also weU irorthy of 
notice.] 

d. Pure, Saturated CW««-ttYwt»*— Fe*C. — By fusing finely divided iron 
or steel with charcoal once or more, a dark grey, fusible carbide of iron 
is obtained, haying a laminar teictore, and capable of being pounded in a 
mortar. (Faraday Sc Stodarl, GU6. 96, 18d.) Bar-steel (uses to a similar 
compound, if the cementation be<»irried too ft^r. (Buttery.) The carbide 
of iron obtained by continued cementation of iron with lamp-black, 
resembles ordinary caat iron in the appearances which it presents at a red 
or a melting heat, and in its reactions with other bodies. (Karsten.) 
4 atoms of iron strongly ignited or fused with excess of charcoal appear 
to take up at most 1 atom of carbon. 

Faraday & Stodart. 

4Fe 108 .... 94-73 94-36 

C 6 .... 5*27 5-64 

Fe^C 114 ..« lOO'OO ZZ 10000 

e, Pe'C. — When Prussian blue is ignited in close vessels, there 
remains a black powder, which, if exposed to the air while still warm, 
takes fire and burns away, yielding carbonic acid and sesquioxide of iron. 
(Proust, Ittner, Berzelius.) Robiquet regards the residue as a mere 
mixture, since it is magnetic, rusts by contact with water, and readily 
gives up its iron to hydrochloric or sulphuric acid, with evolution of 
hydrogen. 

/. FeC^ — Ferrocyanic acid or ferrocyanide of ammonium heated in a 
close vessel, leaves oicarbide of iron, which, when strongly heated in 
nitrogen gas exhibits, a glimmering light unattended with chemical 
change. It is a loose, black powder, which, when slightly heated in 
the air, bums like tinder and is converted into ferric oxide of equal 
weight. (Berzelius.) 

g. Fed — Sometimes left behind, together with graphite, in the 
action of dilute sulphuric or hydrochloric acid, sea-water, &c., on 
unhardened steel and grey cast-iron; it forms a graphite-like but mag- 
netic mass, which oxidizes in the air with considerable evolution of heat, 
is converted into mould by the continued action of acids, and when burnt, 
leaves from 82 to 94 per cent, of ferric-oxide. (Karsten; comp, pp. 204, 
205, 209, 218). — Berthier {Jahrtsher, 14, 130) obtained a similar mass by 
treating cast-steel with aqueous bromine or iodine in quantity not sum- 
cient to dissolve the whole of the iron; it was in the form of the iron, 
could be pressed between the fingers, and was magnetic; it was not 
decomposed by excess of bromine or iodine, until all the free iron was 
dissolved. It contained 81*7 percent, iron and 18*3 carbon; hence its 
formula should be FeC. 

B. Carbonate op Ferrous-oxide, or Ferrous Carbonate, — 
a. Monobasic. — The anhydrous occurs in the forms of Iron-spar, Spathic 
Iron-ore, Stahlstein or SphcBrosiderUej and Junkerite, Iron-spar is isomor- 
plious with calcspar. An acute rhombohedron. Figs. 141, 143, 145; 
r' : r»=72^ 58'; r» : r*=107° 2'. Cleavage parallel to r. (Hauy.) Spe- 
cific gravity 3*829 (Mohs), 3*872 (Neumann). Harder than calcspar; 
white and translucent. In iron-spar, part of the ferrous carbonate is 
often replaced by the isomorphous carbonates of lime, magnesia, and 
manganous oxide. — Junkerite forms yellowish-grey rectangular octo- 
bedronB. {Fig, 47.) Cleavage perpendicular to the axis and parallel to 



226 " IRON. 

two diagonal (angles == lOS'' 26'and '(V 34). Specific giarity 3*815. 
Harder than calcspar. It therefore exhibita with regard to iron-epar the 
same dimorphism that arragonite exhibits with regard to calcspar. 
(Dnfrenoy, Ann, Chim. Fhys, 56, 198; also J. pr, Chem. B, 261.) Ac- 
cording to Breithanpt {Pogg. 58, 278), on the contrary, junkerite has the 
same Form as iron-spar, and the so-called octohedron which it exhibits 
arises from the tmncation of an acnte rhombohedron. Fig. 1 53. 

Iron-spar when heated to redness gives off 4 volnmes of carbonic acid 
cas and 1 volume of carbonic oxide, and leaves black magnetic ferroso- 
rorric oxide: 

6PcO,CO« = 3FcO, Fe»0» + 4C0» + CO. 

(Dbbereiner, Sckw. 28, 43.) According to Fuchs, also {J. pr. Chem, 
17, 168) the residue left after the ignition of iron-spar contains much 
more ferrous and less ferric oxide than magnetic iron-ore. IT According 
to Glasson {Ann. Fharm. 62, 89), iron-spar when ignited out of contact 
of air, gives off 5 volumes of carbonic acid to 1 volume of carbonic oxide, 
and the residual oxide consists of 4 FeO, Fe'O'. IT Hydrate of potash 
likewise converts iron- spar into ferroso-ferric oxide, abstracting the 
carbonic acid and liberating carbonic oxide, but only on the application 
of a considerable degree of heat. (Dobereiner.) In damp air, iron-spar is 
very slowly converted into hydrated sesouioxide of iron. When heated in 
a current of chlorine gas, it yields a suolimate of sesquichloride of iron 
and a residue of sesquioxide, mixed with protochloride if the quantity of 
chlorine is deficient: 

6(FeO, C0«) + 3C1 = 2Fe»0» + FeWJl* + 6C0«. 

(Wohler, Ann. Fharm. 29, 253.) Hydrochloric acid dissolves iron-spar 
but slowly, with evolution of carbonic acid. The mineral does not 
dissolve in aqueous hydrochlorate or nitrate of ammonia. (Brett.) 

FeO 35 61-404 

CO? .^ 22 38*596 



F©0,CO» 67 100-000 

The hydrated ialt is precipitated, on mixing a ferrous salt with 
carbonate of potash or soda, in thick flakes, which, when exposed to the 
air, abstract oxygen and evolve carbonic acid, first assuming a dirty 
green colour, and then changing to yellowish-brown ferric hydrate. 

It is very difficult in preparing this substance (for medical purposes) 
to wash and dry the precipitate without allowing it to undergo the 
change just mentioned, to a considerable extent. — The green vitriol 
used must be perfectly free from ferric sulphate, e. g,, tliat obtained by 
Bonsdorfi^s process, — and this salt, as well as the monocarbonate or bi- 
carbonate of soda or potash used as the precipitant, must be dissolved in 
water perfectly freed from air by boiling. (Bicarbonate of potash gives 
a dense pulverulent precipitate: G. Schmidt.) The precipitation is per- 
formed as much as possible out of contact of air, with excess of the 
alkaline carbonate, and for the most part in the cold. Wilkens and 
Wittstein, however, recommend precipitation at a boiling heat, followed 
by a quarter of an hour's boiling, whereby the fiocculent precipitate 
collects into a powder which is easier to wash. If, however, the liquid 
contains a^ large quantity of carbonate of soda, the precipitate turns 
greyish-black on boiling. (Qeiger.) It is washed with boiling water 



FBRR0U8 CARBONATE. 921 

either on a oloth filter, with frequent agitation and straining, and lastly 
pressed between bricks (BoUe); or, by Schind1er*s method, in a bottle 
with the bottom cut off and bound round with linen, and having a long 
tube filled with boiled water adapted to its mouth, as in Real's press 
(Wilkens); or it is washed by decantation in a stoppered bottle kept 
constantly full of water freed from air by boiling. — The precipitate, after 
thorough washing, is either quickly introduced into a bag of bibulous 
paper, and the whole tied closely up in a moist bladder and dried between 
50^ and 60° (Wilkens); or inclosed in a bladder without the paper 
(Daum). Or the precipitate, after thorough washing by decantation, is 
agitated with alcohol instead of water, the liquid decanted, and the wet 
mass introduced into a tubulated retort, previously connected air-tight 
with a receiver which has been exhausted of air as completely as possible 
by burning alcohol in it. The tnbulus of the retort having been stopped 
and a gentle heat applied, the alcohol passes over and the residue 
becomes dry. If too strong a heat be applied, the carbonic acid escapes. 
(Fdlix.) Or the moist precipitate, after having been covered with ether 
in a retort, is dried at a gentle heat in a distillatory apparatus filled with 
ether vapour (p. 171), after which dry carbonic acid gas is then made to 
pass through the apparatus; by this treatment, the precipitate is rendered 
somewhat less liable to change by exposure to the air. (G. Schmidt.) 

The preparation, when tolerably successful, is a greenish -white or 
dark green, rather heavy, finely divided, and tasteless powder, containing 
from 24 to 80 per cent, of carbonic acid. When ignited out of contact of 
air, it yields water, carbonic acid and carbonic oxide, and leayes 
magnetic ferroso-ferric oxide, which, after cooling in air-tight vessels, 
takes fire on exposure to the air. The moist powder becomes perfectly 
dry after exposure to the air for some days, giving off carbonic acid and 
being completely converted into ferric oxide. When not well dried, it 
oxidizes quickly in the air, becoming very hot and giving off vapour of 
water. But if mixed with sugar while in the moist state, it acquires a 
coating of syrup which renders it more permanent. (Klauer.) When 
treated with hydrochloric acid, it rapidly evolves carbonic acid. {Comp, 
J. A. Buchner, Daum, L. A. Buchner, Wittstein, F. W. Schmid, Repert. 
16, 235 j 41, 279 and 285; 61, 210; 67, 270; BoUe, Berl. Jahrh. 33, 1, 124; 
Fblix, Br. Arch. 38, 149; Wilkens, Klauer, Ann. Fharm. 10, 86; 
19, 129; Vallet, J. Pharm. 24, 289.) 

(. j4cidsaU, Aqueotis soltUion. — Formed by dissolving the normal salt 
—or metallic iron, which dissolves with evolution of hydrogen — in 
aqueoQs carbonic acid, out of contact of air. The colourless solution, 
which has a slightly ferruginous taste, is decomposed with precipitation 
of hydratcd ferric oxide, if the air has access to it even but sparingly; it 
yields a black precipitate with hydrosulphuric acid, and, according to 
Pfaff, a purple precipitate with tincture of galls. According to Vauc^uelin 
(J. Fharm. 13, 266), the black precipitate with hydrosulphuric acid is not 
produced till the solution has been exposed to the air for some time; it 
then forms as the carbonic acid escapes. To preserve chalybeate water 
in vessels, they must first be filled with carbonic acid gas, then filled 
below the surface of water with the chalybeate, and lastly corked under 
water. A less efficient mode of preservation is the introduction of iron- 
wire or of 4 grains of sugar. In sugared chalybeate water, hydrosul- 
phuric acid and sulphide of iron may be detected after the water has 
been kept for a year. (Bischof, Schw, 57, 26; J. pr. Chem, 1, 841.) 



222 IHON. 

C. Ferric Carbonate f-~The precipitate thrown down bj alkaline ear* 
bonates from ferrous salts, contains, after thorongb washing and exposure 
in thin lajrers to the moist air of a cellar for half-a-jear, 71 *4 per cent, of 
ferric oxide (perfectly free from ferrous oxide), 8*3 carbonic acid, and 
20*0 water. (Soubeiran, Ann. Chim, Fhyz, 44, 326; also J. Pkarm. 
16, 524.) — The precipitate formed by mixing carbonate of potash with 
nitrate of ferric oxide consists, after proper washing with cold water^ 
of hjdrated ferric oxide, perfectly free from carbonic acid, (€hn.) 

Iron and Boron, 

According to ArfTodson's experiments, no such compound as Boride 
of Iron appears to exist (vid. II., 100). The so-called horide of iron 
which Lassaigne {J. Chim. Mid, 3, 535) obtained by igniting borate of 
ferric oxide in a current of hydrogen was probably a mere mixture of 
iron and boracic acid. (Qm.) 

A. Borate of Ferrous Oxide, or Ferrofs Borate. — Borax added 
to solution of ferrous sulphate throws down a pale yellow powder, which 
melts before the blowpipe to a bead (Scheele), and from which a large 

?[uantity of acid may be extracted by water. According to Tiinnermann 
Eastn. Arch. 20, 21^, the precipitate is greyish-green, and giyes up all 
its acid when washoa. 

B. Borate of Ferrio Oxide, or Ferric Borate. — ^Yellowisb 
powder insoluble in water: when heated, it turns brown and afterwards 
fuses to a glass. (Berzelius, Lehrb.) 

Iron and Phosphorus, 



A. Phosphide of Iron. — a, Fe*P. — Found by Bergman (Opuse. 8, 
109) and Meyer in cold-short iron, and regarded as a peculiar metal, for 
which the name Siderum or ffi/drosiderum was proposed: it was after- 
wards recognized as phosphide of iron by Meyer, Klaproth, and Scheele. 
— 1. Prepared by passing phosphorus vapour over red-hot iron filings, or 
throwing pieces of phosphorus upon them. (Hatchett.) — 2. By igniting 
iron filings with an equal weight of glacial phosphoric acid, either with 
or without -^ part of charcoal dust. (Pelletier.) Or by exposing 8 parts 
of iron filings, 10 bone-earth, 5 fine quartz-sand, and 1 charcoal- powder 
to a heat sufficient to melt the silicate of lime. (Wohler.) — 3. By i^iting 
phosphate of ferrous oxide with ^ its weight of lamp-black. With a 
larger quantity of lamp-black, a mixture of phosphide and carbide of iron 
is obtained (the latter may be dissolved out by hydrochloric acid); but 
half of the phosphorus always volatilizes during the operation. (Berzelius.) 

Colour dark steel-grey (H. Davy); white, streaked on the fractured 
surfaces (Hatchett). Pulverizable ; specific gravity 0*7. According to 
Hatchett, it is magnetic and may be made polar. Accordinsf to Berzelius, 
on the contrary, it is non-magnetic; hard and susceptible of polish; 
brittle, with granular fracture; sometimes crystallizes in prisms after 
fusion; fuses much more easily than cast-iron. 

Berzelius (3.) Pelletier (2.) 

4Fe 1080 .... 77-47 76805 .... 80 

P 31-4 .... 22-53 23-195 .... 20 

Fe*P 139-4 .... 10000 !ZI 100000 Z. lOo" 



FERKOUS 1>H08PHITE. 22S 

m 

Wlien fused bofoM the blowpipe, it slowly beoomoi eoTeved with a 
Mack slag of phosphate of iron, and gives up its phoephoras but slowly^ 
ereii in the inner flame. Not attacked by cold hydrochlorio, snlphuric, 
nitric, or nitro-hydrochloric acid. Dissolves but slowly in strong nitrio 
or nitro-hydrocbloric acid: the former solution, if formed from 4 parts of 
phosphide of iron, leaves on evaporation Q^S parts of ferric phosphate. 
(Berzelius.) 

b. TvKhthirds Fhogphdde, — Fe'P. — ^Formed by passing phosphoretted 
hydrogen gas over gently heated iron pyrites: 

aFeS* + 2PH» = Fe»P« + 6HS. 

The pnh-emlent compound gives a phosphorns flame before the blowpipe. 
It dissolves in nitric acid and aqna-regia; but not in hydrochloric acid 
even when concentrated* (H. Rose, Fo^g, 24, 333.) 

H. Rose. 



3Pe 

2P 


... 81-0 .... 56-33 
62-8 .... 43-67 


56-87 — 54-92 
4313 — 4508 


Pc»P* 


.. 143-8 .... 100-00 


100-00 — 10000 



B. Hypophosphitb of Ferrous Oxide, or Ferrous Htpophosphite. 
— Iron dissolves in aqueous hypophosphorous acid out of contact of air, 
with evolution of hydrogen gas. The solution evaporated in vacuo yields 
a light green, crystalline mass which when heated m a retort behaves like 
the zinc-salt. (H. Rose, Fogg. 12, 294.) 

C. Htpophosphite op Ferric Oxide, or Ferric Hypophosphitb.— » 
Hydrated ferric oxide dissolves sparingly. in the cold acid; but without 
reduction to the state of ferrous oxide, and forms a white salt which is 
difficultly soluble in the free acid, and when heated gives off easily 
inflammable phosphuretted hydrogen. On boiling the hydrated oxide 
with the acid, a solution of ferrous hypopbosphite is obtained, while ferric 
phosphate is precipitated. 

D. Phosphite of Ferrous Oxide, or Ferrous Phosphite. — Formed 
by precipitating green vitriol with terchloride of phosphorns dissolved in 
water and neutralized by ammonia — ^washing the precipitate, which is 
white, but soon acquires a slight greenish colour, with boiling water — ^and 
drying it in vacuo. During this treatment, the superficial portions 
become oxidized and converted into brown-red basic phosphate of ferrio 
oxide. The filtrate, when kept in a close vessel, deposits a small 
additional quantity of the salt, and then becomes slightly tnrbid on 
boiling. — The dried salt, when ignited in a retort, gives off pure hydrogen 
gas with incandescence and leaves diphosphate of ferrous oxide. The 
residue contains (besides 0'12 p. c. of a black phosphorous-compound 
insoluble in hydrochloric acid) 53*65 per cent, of ferrous oxide and 46*35 
phosphoric acid. (H. Rose, Pogg, D, 35.) 

E. Phosphite op Ferric Oxide, or Ferric Phosphite.— Terchloride 
of phosphorus mixed with water and ammonia yields with double 
sulphate of ferric oxide and ammonia, a white precipitate soluble in 
excess of the iron -salt; this precipitate must be washed with cold water 
and dried in vacuo. The liquid filtered from the precipitate deposits, 
after long standing, a large additional quantity of the salty of a white 



224 IRON. 

coloar.-i-The white salt when heated to rednees in a retort, exhihits a 
glimmering light, gives off hydrogen gas — which contains phosphoms 
and therefore gives a precipitate with silver-solution, hut does not take fire 
spontaneously in the air — and leaves a white residue dotted with hlack 
specks. These spots are due to the presence of a small quantity of a 
hlack phosphorus-compound amounting to 0*9 per cent; the hydrochloric 
acid solution of the residue yields a quantity of ferric oxide amounting 
to 52*46 per cent, of that residue, in which, however, it existed partly in 
the state of ferrous oxide. (H. Rose.) 

F. Phosphate of Ferrous Oxide, or Ferrous Phosphate. — 
a, Terbasic. — Found in the hydrated state, as Blue Iron-ore or Vivianite, 
— Crystalline system, the oblique prismatic. Fig. 81, 82, and other forms. 
u* : w = IIP 6'; t : m= 125'' 18'; Sp. gr. 2'6. Softer than calcspar. 
Indigo-blue, producing a light blue powder; transparent, with a pearly 
lustre. Fuses very readily before the blowpipe, with intumescence and 
loss of water, forming a grey, shining, magnetic bead, and imparting a 
bluish>green colour to the name. Boiling potash-solution extracts phos- 
phoric acid from it and turns it black. Easily soluble in hydrochloric or 
nitric acid. 

Earthy Phosphate of Iron, or Blue Iranrcarth, appears likewise to 
belong to this head; as this mineral is often white when first dug up and 
afterwards turns blue on exposure to the air, it is probable that the 
blue colouring is due to the presence of a certain quantity of ferric 
phosphate. 

3FeO,cPO* + 8Aq. a. *. c. d. e. f. g. 

3FeO....1050 .... 4227 .... 4123 .... 41*0 .... 45 .... 42-65 .... 48-79 .... 42 .... 430 

PO* ... 71-4 .... 28-75 .... 3118 .... 26-4 .... 21 .... 24*00 .... .... 28 .... 231 

8HO .... 720 .... 28-98 .... 27*48 .... 310 .... 34 .... 25*00 .... 26*26 .... 26 .... 32*4 

Sand 7-90 .... Mould 4 

APO«, 0-6;— Mn«0», 0*3 0*9 

248-4 ....100-00 .... 99-89 .... 98-4 ....100 .... 9955 .... ....100 .... 99*4 

a. Vivianite from St Agnes in Cornwall, according to Stromeyer.— 

b. From Bodenmais, according to A. Vogel. — c. From the Isle of France, 
according to Fourcroy & Laugier. — d. From the Mullica Hills, New 
Jersey (the so-called MvUidte), according to Thomson. — e. From Kertsch, 
in the Crimea, according to Segeth. — /. Blu^ Iran-earth from the 
Hagenbruch, near Brunswick, according to Wiegemann. — g. Blue IroTir 
earth from Alleyras, according to Berthier. 

A pit in a town had been filled for centuries with heaps of bones, 
wood, gneiss, &c. On the carbonized pieces of wood, and likewise on the 
micaceous laminte of the gneiss (which contained iron), but not on the other 
constituents of it, were seen white crystals of ferrous phosphate which 
turned blue on exposure to the air. — Iron plates immersed in aqueous 
phosphate of ammonia become covered witn white crystalline ferrous 
phosphate. — If the arm a of the bent tube {App, 4) contains solution 
of blue vitriol, together with a copper rod, the arm b containing phosphate 
of soda with an iron rod, and if the two liquids are separated at h by 
moist clay, and the iron is placed in connexion with the copper, white 
crystalline nodules, which quickly assume a fine blue colour on exposure 
to the air, are formed upon the iron. (Becquerel, Ann, Chim, Phys, 54, 
149.) — % Some iron nails found in the stomach of an ostrich and partly 
enveloped in black animal matter, became covered, after seyeral days' 



FERROUS PHOSPHATE. 225 

exposure to the air, with bine spots, which appeared to arise from the 
formation of triphosphate of ferrous oxide ( Fitrianito). (Schlossberger, 
Ann. Ch. Pharm, 62, 382.) Hardinger (J. pr. Chem. 44, 81) mentions 
the occurrence of crystallized Vivianite in the hollow of a bone in the 
skeleton oT a miner found in an old working at Tamowitz. IT 

h, Bibasic f — Ordinary diphosphate of soda ffives a white precipitate 
with ferrous salts. The precipitate acquires a dirty bluish-green colour 
on exposure to the air. It fuses readily before the blowpipe, and solidi- 
fies in a crystalline mass on cooling : it is not reduced to the state of 
phosphide of iron when heated on charcoal alone, but only on the addition 
of carbonate of soda. (Berzelius.) It is insoluble in water and in ammo- 
niacal salts, but dissolves in aqueous acids and in ammonia. The solution 
in ammonia is of a dingy-yellow colour; and when exposed to the air, 
exhibits first a greenish, and then a brownish turbidity. 

c. Acid Phosphate. — Aqueous phosphoric acid dissolves iron with 
evolution of hydrogen gas, forming an acid salt at first, but afterwards 
the more neutral salt is deposited in the form of a greyish- white substance. 
(Scheele.) The solution yields, with ammonia, a greenish precipitate, 
soluble in excess of ammonia. (A. Vogel.) 

IT G. Pyrophosphate of Ferrous Oxide, or Ferrous Pyro- 
phosphate. — A ferrous salt mixed with pyrophosphate of soda yields » 
white, amorphous precipitate, which, when exposed to the air, immediately 
turns green, and afterwards brown. (Schwarzenberg, Ann. Pharm. 65, 
153.) IT 



H. Phosphate of Ferric Oxide, or Ferric Phosphate. — a. Poly^ 
hone. — Remains in the form of a red-brown, somewhat fusible powder, 
when the sesquiphosphate is boiled with caustic potash. (Fourcroy & 
Vauquelin.) 

Limaniie, Bog Iron-ore (Rcueneisenstein, Sumpfert, Wiesenerz). — Brown^ 
with conchoidal fracture, fusing at the edges before the blowpipe. A. 
nSixture of biba8io( ?) phosphate of ferric oxide, silicate of ferric oxide, 
humus-like ferric oxide, hydrated ferric oxide, quartz-sand, &c. in variable 
proportions. The quantity of phosphoric acid in it varies from 1*8 to 
1 1 per cent. 

h. Bibasic. — <e. Ore from the Dpt. de la Haute Vienne. Brown needled 
arranged in radiated masses, producing an olive-green powder, and fusing 
before the blowpipe to a black opaque glass. (Vauquelin, Ann. CMm.. 
Phys. 30, 202.) Of similar nature is Oreen Iron-stone. (Karsten, in his 
Archiv. 15, 243.) 



2FeH)» 1660 .... 61-32 

MnO 

PO» 71-4 .... 2807 

3HO 27-0 .... 10-61 



Vanqaelin. 




Kanten. 


56-20 


.... 


63-45 


6-76 






27-84 


•w. 


27-72 


9-20 


.... 


8-55 



2Fe»0», P0» + 3Aq. 254-4 .... 100-00 100-00 .... 99-73 

j9. Ore from Bemean, in the district of Liege. Kidney-shaped, with 
a eonchoidal, waxy fracture. Sp. gr. 1 -85. Blackish, reddish, or yellow- 
ish brown; yields a brownish-yellow powder. Translucent at the than 
edges. Decrepitates before the blowpipe, and yields a grey, nagneise 
bead. Falls to pieces in water; easily soluble in dilute hydrochloric acidL 
(Delvaux, BtUl. dc rAcad.de Brmettes, 1888; 147; Dnmont, i>$^47,496.) 

VOL. V. ^ 



226 IRON. 

In the analyses, an admixtuTe of 10 or 11 per cenl. of isazbonate of lime 
and betwe^i 0*5 and 8'6 of silica has been deducted. 

Delvaux.] Dnmont. 

Approximate Calculation. Black-brown. Med-brovm. 

2Fe20» 1560 .... 38-29 .... 40-44 .... 3662 .... 3419 

PO* 71-4 .... 17-53 .... 18-20 .... 1657 .... 1604 

20HO 180-0 .... 44-18 .... 41*13 .... 46-81 .... 49-77 

2Fe2O3,PO« + 20Aq. 407*4 .... 100-00 Z 9977 ... 10000 .... 10000 

Berauniie, wbicli crystallizes in ill-defined rbombic prisms, contains a 
tolerably large quantity of water, together witb ferric phosphate free from 
ferrous oxide. Sp. gr. 2*878. Colour, hyacinth-red; translucent, with a 
pearly lustre. Fuses readily before the blowpipe, and dissolves easily in 
hydrochloric acid, leaving only a trace of silica. (Breithaupt & Plattner^ 
/ pr, Chem. 20, 66.) 

On Karphosiderite, vid. Breithaupt. (Schw, 50, 314.) 
MelanMore from Rabenstein, which has a density of d'38, fuses readily 
before the blowpipe into a black magnetic bead, and is easily soluble in 
warm hydrochloric acid. Contains, besides impurities, about 3*87 per 
cent, of ferrous oxide, 38*9 ferric oxide, and from 25*5 to 30*3 phosphoric 
acid. (Fuchs, J. pr. Chem, 17, 171.) 

c. SeaquipkosphcUe, — By precipitating sesqnichloride of iron with 
ordinary diphosphate of soda: 

2Fe2Cl» + 3(2NaO,cPO«) = 2Fe«05, 3cP0« + 6NaCl. 

This calculation, however, is not in accordance with A. Vogel's analysis, 
which gives 37 per cent, ferric oxide, 38 acid, and 24 water. The white 
flocculent precipitate retains its colour when dry ; but at a red-heat it 
gives off water, turns yellow, and afterwards fuses to a grey bead. (Bei^- 
man, Opusc. 3, 118.) With carbonate of soda upon charcoal, it yields 
phosphide of iron. (Berzelius.) Caustic potash immediately colours the 
precipitate red-brown, by withdrawing the greater part of its acid, biit 
does not dissolve any ferric oxide. Ammonia exhibits the same reaotion, 
provided no phosphate of soda is present in excess; in the latter case, the 
ammonia turns the precipitate brown and then dissolves it, forming a red- 
brown solution. The ammoniacal solution remains clear when mixed 
with ferrocyanide of potassium, but yields Prussian blue on the addition 
of an acid. (H. Rose, Fogg, 43, 587.) The salt can only be separated 
from the ammoniacal solution by evaporation. (Dobereiner, Schw, 26, 
271.) Carbonate of ammonia likewise dissolves the precipitate. (Berze- 
lius, Pogg, 27, 131.) When immersed in carbonate of soda, it slowly 
acquires a red- brown colour, and dissolves partially in a large excess of 
the liquid. (H. Rose.) The salt dissolves in 1500 parts of boilint; water, 
and easily in dilute acids. (Bergman.) It does not dissolve in cold acetic 
acid, or in aqueous ammoniacal salts. (Wittstein, ReperL 63, 224.) The 
freshly precipitated salt dissolves slowly in warm aqueous snlphurons acid 
or sulphite of ammonia, the ferric oxide beiug reduced to the state of 
ferirous oxide. (Berthier.) 

d, Biphoaphate ? — The solution of the salt c in aqueous phosphoric 
acid, when kept for a year in close vessels, yields small, translucent, taste* 
less cubes, having a vitreous lustre (sometimes with a pale rose-colour, 
arising from the accidental presence of manganese). When heated, they 
give oft water, and leave a dirty white, opaque maas, which^ at a bright 



DISULPHIDS 07 IRON. 227 

red heat, ttma^ to a grey elag. They are insolable in water, bat dimolTd 
in ammonia, fonning a red solntion, and yery easily in hydrochloric acid, 
forming a light brown solution. (Winckler, JkepeH. 38, 197.) 

Jpprosiwutte CaleuIaHan. Wmckler. 

Fc^O* 780 .... 26-63 250 

2PO» 142-8 .... 48-77 525 

8HO 720 .... 24-60 22-5 



Fe«0«,2PO* + 8Aq 292-8 .... 10000 1000 

IT I. Ptrophosphatb of Ferric Oxide, or Perric Pyrophosphatb. 
— Obtained by dissolying sublimed sesquicbloride of iron in water, and 
precipitating by phosphate of soda; the supernatant liquid is neutral. 
Nearly white powder, haying a slight yellowish tinge, which deepens at 
100°, and becomes lighter again after ignition. Dissolyes in acids and in 
phosphate of soda, likewise in ammonia; in the latter it forms a yellow 
solution. Insoluble in hydrochloric acid, sulphurous acid, and sal- 
ammoniac. On dissolying it in hydrochloric acid without boiling, and 
precipitating by ammonia, the precipitate dissolyes completely in excess 
of ammonia. Carbonate of ammonia dissolyes it, forming a colourless 
solution, whereas the ordinary phosphate forms a yellow solution. It is 
completely decomposed by fusion with a mixture of carbonate of soda and 
carbonate of potash. The salt, after drying at 100% lost by ignition 
17*66 p. c. of water, and the ignited siut was found to contain 41*7 
Fe»0' + 58-3 PO*. These numbers accord with the formula 2Fe»0',36PO» 
+ 9 Aq. 

Acid sesquicbloride of iron, precipitated by pyrophosphate of soda» 
yields, not pyrophosphate of ferric oxide, but an ordinsiry phosphate^ 
containing 1 atom of base to 1 atom of acid; in 100 parts : 61*66 FeK)' + 
48*34 PO^ This salt, when boiled with ordinary phosphate of soda, does 
not yield pyrophosphate of soda^ as is the case with the preceding. 
(Schwarxenberg, Ann* Fkarm, 65, 153.) 

K. Metaphosphate op Ferric Oxide, or Ferric Metaphosphatb. 
—Formed by mixing sesquicbloride of iron with excess of dilute phos- 
phoric acid, eyaporatmg to dryness, and heating the residue in a platinum 
capsule to 316°. White powder, insoluble in water and in dilute acids, 
but soluble in strong sulphuric acid. Contains 26*35 per cent, of Fe^C, 
corresponding to the formula^ Fe'0*,3P0^ (Maddrell, Ann, Fharm. 61, 
59.) T 

Iron and Sitlpbxtr. 

A. One-etobtb Sulphide op Iron. — Formed by passing hydrogea 
gas oyer red-hot disnlphate of ferric oxide; water is formed, sulphnroofl 
acid and a large quantity of hydrosulphuric acid giyen off,— -and there 
remain 59*52 parts of sulphide of iron for eyery 100 parts of the dry salt 
used. Blackish-grey powder, producing a grey metallic streak. Contains 
27 parts of iron to 2 pts. sulphur. When treated with dilute acids, it 
yields 7 yolumes of hydrogen gas to 1 yolume of sulphuretted hydrogen, 
(Arfyedson, Fogg, 1, 72.) 

B. Disulphide op Iron. — 100 parts of anhydrous sulphate of ferroiw 
oxide, decomposed by hydrogen gas at a red heat, yield at first sulphuroiB 
acid and water; then hydrosulpharic acid, and leaye 40*74 parts of disul- 

q2 



228 tkoii^ 

phide of iron. Dark grey powder aggregated in lanips, strongly attracted 
by the magnet; contains 27 iron to 8 sulphur. Hydrosulphuric acid gas, 
passed over it at a red-beat, converts it into the sulphide of iron, corres- 
ponding to magnetic pyrites, whereby 35 parts are increased to 45. 
Dissolves in aqueous acids, with evolution of 4 vol. hydrogen ffas to 1 vol. 
hydrosulphuric acid. When a mixture of 20 parts protosulpnide of iron 
and 12 of iron wire is fused in a charcoal crucible, 2 layers are formed, 
the lower of which is cast-iron containing 2*5 per cent, of sulphuiv—from 
admixture of sulphide of iron — while the upper layer consists of proto- 
sulphide of iron mixed with a small quantity of cast-iron, often distin- 
guishable by the eye. (Berthier, Ann, Ckim, Phys, 22, 241.) Perhaps 
the presence of carbon hindered the formation of a lower sulphide ; for, 
according to Berzelius, protosulphide of iron dissolves metallic iron at a 
strong heat, producing a lower sulphur-compound. 

C. Protosulphide of Iron, or Ferrous Sulphide. — Occurs in small 
quantities in many meteorites; sometimes formed by the reducing action 
of putrefying organic bodies on ferrous sulphate contained in well- 
waters, — ^but under such circumstances it is always mixed with a higher 
sulphide. (Berzelius.) Heated iron-wire bums vividly in sulphur vapour 
(II, 221). A mixture of iron-filings and sulphur glows vividly when 
heated. Sulphur pressed against red-hot bar-iron (not cast-iron) per- 
forates it by forming sulphide of iron. (Evain, Ann, Chim. Phys. 25, 
106; also Sc/iw. 43, 330.) — Preparation. 1. Iron-plate cut into strips is 
gently heated in a covered crucible with sulphur not in excess, and the 
resulting sulphide separated by bending the iron. Sulphide of iron thus 
obtained is free from excess of sulphur. If the hea£ applied is too 
strong, the sulphide fuses together with the remaining iron; if the sul- 
phur is in excess, magnetic pyrites is formed. (Berzelius.) — 2. By ignit- 
ing iron-filings with two-thirds their weight of sulphur in a covei^d 
earthen or cast-iron crucible. The iron-filings are either disposed in a 
layer above the sulphur or the two are mixed (II, 221, a and 6). In 
either case, the crucible is surrounded and covered with dead coals, and a 
few live coals laid upon the top; as soon as the whole is red-hot, the 
door of the furnace is closed. (Proust, J. Phys. 91, 271.) — 3. Sulphur is 
held against a red-hot iron-bar, and the sulphide of iron, as it runs off, 
allowed to drop into water; or a bar of iron is repeatedly heated to 
whiteness and dipped into melted sulphur contained in a cast-iron crucible 
and frequently renewed. (Gahn.) — 4. A finely divided mixture of scale- 
oxide of iron and sulphur is heated to redness. — 5. Iron pyrites is heated 
to redness, either alone or with a small quantity of iron-filings. The 
methods 2, 3, 4, and 5 may likewise yield the following sulphur com- 
pound, corresponding to magnetic pyrites; but when sulphide of iron is 
heated till it fuses, the residue, according to Bredberg, always consists of 
protosulphide of iron. — 6. By igniting anhydrous ferrous sulphate in a 
crucible lined with charcoal. The product contains, however, only 34 
per cent, of sulphur, likewise moj-e or less carbon. (Berthier, Ann, Chim, 
Phys, 22, 241.) — 7. By igniting 1 part of iron-filings with 1 part of 
charcoal-powder and 4 parts of lead-sulphate, whereby metallic lead is 
obtained at the same time. (Fischer, N, Tr, 6, 1, 298.) — Yellow, with 
metallic lustre; yields a yellowish powder; it is attracted by the mag- 
net. The protosulphide obtained by fusing iron pyrites is less hard 
than the bisulphide, and, on exposure to the air, crumbles to a bulky 
powder which emits a disagreeable odour when touched with wet hands* 



PROTOSULPHIDE OF IRON. * 229 

(Bredberg, Pogg, 17, 271.) — ^Wben iron pyrites is ignited in a current of 
hydrogen gas, the protosalphide is obtained in the form of a blackish- 
grey, non-magnetic powder, which dissolves in hydrochloric acid without 
separation of sulphur, and at the same time gives off pure bydrosul- 
phuric acid gas. (H. Rose, Fogg. 5, 533.) The protosnlphide obtained 
by igniting magnetic pyrites in hydrogen gas is non-magnetic. (Count 
Sohaffgotsoh.) 

Bncholz & Van- 
ProQst. Berzelioi. Hatchett. Gehlen. qnelin. 

Fc .... 27 .... 62-79 .... 625 .... 63 .... 63 to 63-5 .... 634 .... 78 
S 16 .... 37-21 .... 37-5 .... 37 .... 37 „ 36'5 .... 36*6 .... 22 

FeS... 43 .... 100-00 .... 100*0 .... 100 .... 100 „ lOO'O .... 100-0 .... 100 

Protosnlphide of iron gives off no sulphur when heated, even to white- 
ness, in a close vessel; and, when raised to a white heat in a charcoal 
crucible, it increases but slowly in weight. (H. Rose.) — When gently 
heated in the air, it is partly converted into sulphate of ferrous oxidej 
but at a stronger heat, sulphurous acid is evolved and ferric oxide remains 
behind. With nitrous acid it evolves nitrous eas, ferric oxide and sul- 
phuric acid being formed and sulphur separated. — It dissolves in dilute 
sulphuric or hydrochloric acid, with evolution of pure hydroslilphuric 
acid gas perfectly soluble in caustic potash, and without -separation' of 
Bulphur. (Berzelius.) — Aqueous vapour passed over red-hot sulphide of 
iron converts it, with evolution of much hydrogen and sulphuretted 
hydrogen gas, into a black and partly magnetic mass. The water forms 
with the sulphide of iron, hydrosulphuric acid and ferrous oxide, which, , ' 
by further decomposition of water, yields hydrogen gas and ferroso- ferric 
oxide; but a portion of the sulphur remains, even afW three-hours' 
Ignition. (Regnault, Ann. Chim. Phys. 62, 379.) — Chlorine" gas does not 
decompose cold sulphide of iron; but that compound, when heated in the 
gas, yields chloride of sulphur and sublimed sesquichloride of iron. 
(H. Rose, Pogg. 42, 540.) — Protosnlphide of iron, heated to low redness 
with once or twice its weight of carbonate of soda or potash, fuses into a 
black, crystalline, highly magnetic mass, from which water extracts 
sulphide of sodium or potassium, with a trace of sulphuric acid. " 43 pts. 
(1 At.) of sulphide of iron heated to whiteness in a charcoal crtiliible 
with 53 pts. (1 At.) of dry carbonate of soda, yields 21 parts of cast- 
iron and a black laminar slag. Baryta and lime behave in the same 
manner, only that the viscidity of the slag prevents the iron from fusing 
into a mass. (Berthier, Ann. Chim. Phys. 31, 170.) When protosnlphide 
«of iron is fused with 30 times its weight of protoxide of lead, the whole 
of the sulphur is given off in the form of sulphurous acid, metallic lead is 
.separated, and a fused mixture of protoxide of iron and protoxide of lead is 
produced. 1 part of sulphide of iron, heated with 5 parts of litharge, boils 
•up, fumes, and forms a pasty semifluid mass, which, on cooling, solidities into 
-a metal-grey, homogeneous, highly magnetic elag, containing sulphide of 
iron and sulphide of lead. — With 10 parts of litharge, the mixture swells up 
strongly, becomes very fluid, and yields 3*6 parts of lead, together with 
-a metal-black, magnetic slag. With 25 parts of litharge, the mixture 
-yields 6*7 parts of lead and a dense, glassy, red, transparent slag. A 
mixture containing 30 parts of litharge, yields 7 parts of tolerably pure 
lead, and the slag, which has the same appearance as that last menlaoned, 
uo longer contains any metallic sulphide. (Berthier. Ann* Chim. Phys, 
39,253.) 



230 IRON* 

Hydraied Protosulphide of Iron, or Eydrosulphate of Ferrous Oxidt. 
1. Alkaline bjdrosolpbates form with ferrous salts a black flooculent 
precipitate. — 2. Twenty-seveu parts of iron-filings and 16 parts of sulphor 
made into i^ paste with water^ and kept out of contact of air, aggregate 
into a black mass, with strong evolution of beat; this effect takes place 
more quickly on the application of heat — 3. Iron-filings in contact with 
sulpburettea hydrogen water liberate hydrogen gas almost free from 
sulphur, and turn black; part of the resulting hydrosulphate of ferrous 
oxide dissolves in the water. (Vauqnelin.) — The black compound oxidates 
quickly in the air, forming water, ferric oxide, and sulphur or sulphuric 
acid; and, even if it be kept for several weeks before being exposed to 
the air, the action is attended with an evolution of heat, which, if the 
mass is considerable, may even produce inflammation. The Artificial 
Volcanot qf Lepiery are formed by mixing several pounds of iron-filings 
with ^ to -{• of its weight of sulphur, making the mixture into a paste 
with water, and burying it in the ground. — Hydrated protosulphide of 
iron decomposes the salts of cadmium^ lead, copper and silver, precipitat- 
ing the metals as sulphides. (Anthon.) — It dissolves in dilute acids much 
more quickly than the anhydrous sulphide, and with violent evolution of 
sulphuretted hydrogen. — It dissolves in small quantity in water (espe- 
cially in hot water : Berzeliui)^ forming a solution which has a dark green 
colour and inky taste. (Yauquelin, Scker. J, 6, 63; also GHh. 9, 42.) 
The presence of hydrosulphuric acid or hydrosulphate of ammonia in the 
water prevents the solution; and any sulphide of iron previously dissolved 
in pure water is precipitated on the addition of hydrosulphate of ammonia 
and the application of heat. (Berselius.) According to later investigations 
of Vauquelin («/. Pharm, 13, 266), iron-filings and sulphuretted hydrogen 
water, placed together in a close vessel for four-and -twenty hours, yield, 
after filtration, a colourless solution which blackens quickly on exposure 
to the air. According to 0. Henry («7. Pharm, 24, 118), when a solution 
of green vitriol is precipitated with excess of aqueous sulphide of calciumi 
ft small quantity of iron still remains dissolved. 

The olack mud at the bottom of drains contains hydrated sulphide of 
iron, probably formed by the putrefaction of organic substances in contact 
with the ferric oxide of earthy matters, and to this it owes its black 
eolour and peculiar smell. Hence, when exposed to the air, it loses its 
odour and colour, and afterwards resembles ordinary vegetable mould. 
With hydrochloric acid it evolves abundance of sulphuretted hydrogen; 
to boiling potash it gives up sulphuretted hydrogen together with organic 
matter. The black colour of the soil in privies, pits, ponds and morasses, 
and of the sand between the pavement of streets [also of faaces after the 
administration of medicines containing iron] is likewise due to hydrated 
sulphide of iron. (Braconnot, Ann, Chim. Phys, 50, 213.) 

D. EiGHT-SBVENTHS SuLPHiBE OF Iron. — Found native in the form 
of Magnetic Pyrites,- This mineral crystallizes in forms belonging to 
the hexagonal system. Figs, 132, 135, 136, 137, 138 and others. p:r 
(Fig. 132)=102° 13'; p :r (Fig. 136)=105^ Cleavage parallel to p. 
Harder than calcspar; sp. gr. 4*5 to 4'7; brittle; with conchoidal frac* 
ture. Colour varying from bronze-yellow to brown ; powder greyish- 
black. Acted on by the magnet, and often itself magnetic. According 
to Berzeliue^ it doQs not give off sulphur when ignited out of contact of 
air. Fuses on qharcoal before the blowpipe, forming a greyish-black, 
strongly magnetic globule. When roasted in the state of fine powder, it 



SESQXnSULPHIDE OF IRON. 231 

18 oonverted into pore ferric oxide. When ignited in a oanrent of hydro- 
gen gas, it loses so much solphor that it is converted into the proto- 
sulphide. (The same result was obtained by Plattner, I^ogg. 47, 369.) 
It likewise gives up its excess of sulphur to boiling caustic potash, while 
a mass resembling the hydrated protosnlphide remains behind. (Count 
Schaffgotseh, Fogg. 50, 533.) When heated to whiteness in a charcoal 
crucible, it diminishes in weight but slowly. It exhibits the same decom- 
positions as the protosnlphide, excepting that, when it is dissolved in 
dilute hydrochloric or sulphuric acid, not only is hydrosulphuric acid 
gas evolved, bat sulphur is likewise precipitated in the form of powder. 
(Stromeyer.) The separated sulphur is dark grey^ because it contains 
Bndeoomposed sulphide of iron. (Schaffgotseh.) 

According to Berzelins, the same compound, and not the proto- 
snlphide, is formed by igniting iron or the scale-oxide with excess of 
snlphur, by heating iron pyrites to redness, and by igniting the one-eighth 
sulphide or the disulphide of iron in hydrosulpbuFic acid gas. — The arti- 
ficial compound is brownish bronze-yellow and susceptible of magnetic 
action^ and, according to Hatchett ifiUh, 25, 58), may likewise be ren- 
dered permanently magnetic. 

ScfaaffgotBch. H. Rose. Stromeyer. 

M€tgneiie Pyriin. BodtunuM. Freiburg. 

7Fc 189 .... 59-62 .... 60'5* ... 60-95 .... 59*85 

8S 128 .... 40-38 .... 39-41 .... 39*05 .... 40-15 

6iI^,FeB2.... 517 .... 10000 .... Ia0*00 .... 10000 .... 100-00 

Plattner. Stroineyer. 

Ffthlun. Brazil. Barnes. 

Fe 59*72 .... 59*64 .... 53*37 

S 40*22 .... 40*43 .... 43*63 

99-94 Z 100*07 Z. 100-00 

For analyies of magnetic pyrites, in which a small part of the iron is replaced by nirkel, 
vid, Th. Scheerar (Fogg, 58, 318), and Berzelios (JaArmber. 21. 2, 184). 

£. Sbsquisulphide of Iron, or Ferrio Sulphide. —1. Formed by 
heating protosnlphide of iron mixed with sulphur to very low redness, 
till the excess of sulphur is expelled. (Proust, Sc/aer. J. 10, 54; also Gilb. 
%5, 54. Bttcholz fit Gehlen, iV. Gthl. 9, 2B1.)— 2. By pasising hydrosul- 
phuric acid gas over ferric oxide heated not above 100", as long as water 
continues to be formed. The transformation goes on without any altera- 
tion of form; the artificial hydrated sesquioxide is decomposed, even at 
ordinary temperatures, with slight evolution of heat, only requiring the 
heat of a water-bath towards the end of the operation ; the moisture is 
afterwards driven off in vacuo. (Berzelius.) — Greenish-yellow (Proust); 
yellowish-grey (Bucholz Sc Gehlen, Berzelius); acquires a higher polish 
under the burnishing steel, and when gently heated in vacuo, becomes 
yellower and more lustrous (Berzelius). Magnetic, according to Proust; 
non-magnetic, according to Berzelius. 

Proust. Bnchok & Gehlen. 

2Fe 54 .... 52-94 .... 52*64 .... 52*64 to 52 07 

3S 48 .... 47*06 .... 47*36 .... 47*36 „ 47'93 

• Fe«S> 102 .... 10000 .... 100*00 Z 10000 ,, 10000 

By stronger ignition it gives off sulphur, and is rednced to the eight- 
sevenths sulphide. In the dry state it remains nsaltered in the air; but 



SS2 IRON. 

if exposed while yet moist— as in the state in which it is obtuned by the 
action of surphuretted hydrogen on ferric oxide at ordinary temperatares 
•—it is completely converted, in the course of a few hours, into a roixtnre 
of ferric oxide and snlphur. By dilate hydrochloric or snlphnric acid, it 
is converted into snlphnretted hydrogen, a ferrous salt, and bisulphide of 
iron, which latter still retains the form of the sesquisulphide; but^ so long 
as it remains moist, may be reduced by pressure to the finest powder. 
(Berzeiius.) 

Hydrated Suquindphide of Iron, or HydrotulphoBte of Ferric Oxide. 
^-Formed by dropping an aqueous solution of a ferric salt into an 
excess of alkaline hydrosulphate. If, on the contrary, the alkaline 
hydrosulphate be dropped into an excess of the ferric salt, sulphur is first 
precipitated and a ferrous salt produced, from which an additional quan- 
tity of alkaline hj^drosulphate throws down hydrosulphate of ferrous 
oxide. — Black precipitate, which oxidises quickly in the air. (Berielius.) 

F. BisutPHiDB OF Iron. — Found in nature as Iron Pyrke$ {ScktvefelUei 
or Eisenkies), and as White Iron Pyrites, Radiated Iron Fyriia, or Cock^- 
eomh Pyrites (Strahlkies, Wanerhies, or Speerkies). Each of these varieties 
of iron pyrites is often produced by the action of oiganic substances on 
water containing iron, together with salts of sulphuric add. On a sand- 
heath overgrown with Erica — ^the root-stratum of which smelt strongly of 
hydrosulphuric acid — ^portions of the Arundo PhragmUee were found to 
be partially covered with steel-grey laminsD and crusts of a sulphide of 
iron not soluble in dilute hydrochloric acid. (Meinecke, Schw. 28, 56.) — 
Link found iron pyrites in the mud of ponds. — Bakewell found the 
remains of mice preserved in a bottle filled with solution of green vitriol, 
covered with small crystals of iron pyrites.— -The hot spring of Ghaude- 
saigues, which contains sulphate of soda and other salts and a mere trace 
of iron, deposits iron pyrites in the [wooden f] channel by which the water 
is discharged. (Longchamp, Ann, Chim. Phys, 32, 294.) On digging in 
the neighbourhood of the chalybeate spring at Rondorfer, which contains 
acid carbonate of ferrous oxiae and sulphate of soda, the bo^gy ground 
and the fragments of quartz scattered about, were found to be covered 
with iron pyrites. (Noggerath k Bischof, Pogg. 38, 407.)— A simihur case 
is described by Gilbert. {Gilb. 74, 206.)— A ferruginous water which 
ran from a basm formed out of the hollow trunk of a tree, yielded, when 
recently drawn, a large quantity of blackish-yellow iron pyrites, contain- 
ing a portion of vegetable matter enclosed within it, and, moreover, 
44-78 iron to 5522 sulphur.— A quantity of the Brohl mineral water, 
which contains very small quantities of iron and sulphate of soda, having 
been mixed with a little sugar and kept for three years in closed vessels, 
was found to smell of sulphuretted hydrogen, and had deposited a black 
powder which appeared to contain serauisulphide of iron together with 
free sulphur. In a similar manner, white iron pyrites appears to be 
formed in black and in brown coal. (Bischof, Schw. 64, 377.) 

Preparation, 1. Ferric oxide, ferroso-ferric oxide, hydrated ferric oxide 
or carbonate of ferrous oxide, natural or artificial, in powder or in crystals, 
ia exposed, at a heat exceeding 100° but not amounting to redness, to a 
current of sulphuretted hydrogen, as long as the mass continues to increase 
in weight. At first the action is so strong, that aqueous vapour, sul- 
phurous acid, and hydrogen gas are evolved, and lower sulphides of 
iron are formed, which afterwards take up more sulphur and liberate puw 



BISULPHIDE OF IRON. 233 

liydrogen gas. The sulphide of iron thus produced retains the crjstalliue 
form of the oxide used in its preparation, with the same lustre on the faces;, 
and the same directions of cleayage. (Berzelius.) — 2. The lower sulphides 
of iron may be brought to this, the highest degree of sulphuration, bj 
heating them in like manner in hydrosulphuric acid gas. (Berzelias.)— 
3. An intimate mixture of 2 pts. protosulphide of iron and 1 pt. sulphur, 
heated in a retort to a temperature short of redness, leaves bisulphide of 
iron in the form of a bulky, dark yellow, non-magnetic, metallic powder, 
not attacked by hydrochloric acid. (Berzelius.) — 4. When an intimate 
mixture of ferric oxide, sulphur, and sal-ammoniac is heated to a tem- 
perature a little above that at which the sal-ammoniac sublimes, the 
residue is found to contain small, brass-yellow octohedrons and cubes, 
which may be separated from the rest of the powder by levigation. 
(W&hler, Pogg, 37, 238.) — 5. When sal-ammoniac containing sulphate of 
ammonia is sublimed at a dull red heat in iron vessels coated with day^ 
the clay covering becomes impregnated with chloride of iron, and cubes 
and octohedrons of iron pyrites form upon its surfsrce. (Lowe, «7. pr, CJiein, 
6, 98.) 

Iron pyrites crystallizes in forms belonging to the regular system : 
Fig9, I, 2, 4, 6, 11, 18, 19, 20, and many others. It gives sparks with 
steel.; Sp. gr. 4*9 to 5*1. Fracture, conchoidal. Colour, bronze-yellow. 
The crystals of white iron pyrites belong to the right prismatic system : 
Fig. 54, 61, and other forms, u : %i {Fig, 54)=73** 24'; uf : u (Fig. 61) 
= 106'' 36^ i :t^=32'' 12^. Cleavage parallel to u and vl, less distinct 
parallel to p, (Hany.) Sp. gr. 4*6 to 4'8. Harder than felspar. Green- 
ish-^ellow-grey inclining to steel-grey; powder greenish-grey. — Iron 
pyrites is non-magnetic in all its forms. 

Ordinary Iron Pyriiti, 
Berzelias. Hatchett. Gueniveau. 

Pe 27 .... 45*77 .... 4608 .... 45-7 to 478 .... 46*6 to 4724 

28 32 .... 64'23 .... 53-92 .... 64-3 „ 52*2 .... 53-4 „ 5276 

FeS^ 59 .... 10000 .... 100-00 .... lOO'O 100-0 .... 1000 lOO'OO 

White Iron Pyritei, 
Bncholz. Berzelius. 

Pe 49 4507 

S 51 53-35 

Mn 0-70 

SiO« 080 



PeS« 100 99-92 

Bisulphide of iron ignited not very strongly in a close vessel, gives off" 
sulphur, and is converted into the eight-sevenths sulphide; at a strong 
red heat it is reduced to the protosulphide. A lower temperature will 
suffice if hydrogen gas be passed over the substance, although the hydro- 
gen does not form hydrosulphuric acid, but appears to act like any other 
gas [by adhesion]. (H. Rose, Pegg. 5. 533.) — The residue has the form 
and colour of the onginal iron pyrites, but its bulk is increased; it is dull, 
exhibits all over its surface cavities formed by fusion, and may be crum- 
bled to pieces by pressure with the Bnger. (rroust, Scher. J. 9, 378.) — 
When ignited with charcoal it yields bisulphide of carbon. — When heated 
in a current of phosphuretted hydrogen gas to a temperature short of that 
at which it evolves sulphur, it yields phosphide of iron and hydrosul- 
phuric acid. (p. 233.) — When heated in the air, it yields sulphurous acid 



334 IROK« 

and salpliaie of ferrous oxide, or, at a higher temperatnie^ enilphiiroiia 
aoid and basic sulphate of ferric oxide. 

Witli nitric or nitro-hjdrochloric acid, it yields ferric oxide, sulphario 
acid, and sulphur. It resists the action of hydrochloric and of dilate sul- 
phuric acid. — Iron pyrites heated with lead-oxide, fuses readily and gives 
off sulphur in the form of sulphurous acid; for the complete expulsion of 
the sulphur, 50 parts of lead-oxide are required to J part of pyrites. 
"With 6 parts of litharge to 1 iron pyrites, 2 layers are obtained ; the 
lower, which contains the larger quantity of matter, is a sulphide of lead 
containing excess of lead ; the upper layer is a lead-grey, magnetic mix- 
ture of sulphide of lead, sulphide of iron, and metallic oxides. — With 
12*5 pts. litharge, the mixture yields 3*5 pts. of lead, rendered somewhat 
brittle by the presence of 1 per cent, of sulphur and a small quantity of 
iron, together with a black, opaque, yitreous slag. — With 20 ports of 
litharge, the same products are formed, the lead, which in this case also is 
somewhat brittle, amounting to 4 parts. With 30 parts of litharge, 4'55 
parts of lead are obtained; with 40 pts. litharge, 5 48 lead; and with 50 
litharge, S'6 lead, together with a transparent red glass. The quantity 
of lead does not exceed 8*6 parts, even if more than 50 parts of litharge 
are used. (Berthier, Ann. Ghim. Fhys, 39, 253.) 

Most yellow iron pyrites, and likewise the white variety when well 
crystallized, remain unaltered in moist air. But many crystals of auri- 
ferous iron pyrites exhibit marks of conversion into hydrated ferric oxide, 
and white iron pyrites often becomes quickly covered with effloresced 
ferrous sulphate. — The efflorescence shows itself only on irregularly 
crystallized masses of the white pyrites, such masses containing proto- 
sulphide of iron mixed with the bisulphide. The latter only is made to 
effloresce by being formed into a galvanic circuit with the more negative 
bisulphide. Hence the ferrous sulphate which effloresces out contains but 
1 atom of sulphuric acid, and when dissolved in water deposits ochre on 
exposure to the air, whereas if formed from the bisulphide, it would 
have contained 2 atoms of acid. The bisulphide remains quite unaltered; 
is split up by the crystals of ferrous sulphate; and after being washed 
with water shows no traces of free sulphur. A mass which will effloresce 
in 12 hours and expand to a tenfold bulk in 4 days by formation of green- 
vitriol crystals, may be artificially produced by exposing ferric oxide to 
the action of hydrosulphuric acid, and stopping the process before the 
conversion into bisulphide is complete, so that some of the lower sulphides 
of iron may remain mixed with it. The same considerations serve to 
explain why iron pyrites exposed to imperfect ignition, whereby a part 
only of the bisulphide of iron is converted into protosulphide, acquires a 
tendency to effloresce. (Berzelius.) — Fournet {Ann, Chim. Fhys, 55, 256) 
attributes the efflorescing property of white iron pyrites to a forced state 
of aggregation of the particles. — The ferrous sulphate effloresced out of 
the white iron pyrites of Schriesheini, when extracted by water, was 
found by the author to yield a solution which did not become at all turbid 
by the addition of a small quantity of potash or by prolonged exposure to 
the air; and the washed residue contained free sulphur which showed 
itself in yellow specks and could be extracted by caustic potash (compare 
also H. Rose, p. 245). — Since the efflorescence of sulphide of iron is 
attended with evolution of heat, we may hence account for the inflamma- 
tion of coals containing that mineral, when they are heaped up in 
considerable masses (either within or without the mine) and exposed to 
'^ir and moisture. (Berzelius.) 



FERROUS HYPOSULPHITE. 235 

6. Sulphide of Ferrous Oxide? — Formed by heating ferrio oxide with 
powdered sulphur to a temperature short of redness, till sulphurous acid 
gas is no longer evolved. — Cbesnat-browu powder^ attracted by the 
magnet. — ^Diasolves with difficulty in hydrochloric acid, sulphur being 
precipitated but no sulphuretted hydrogen evolved. Takes fire in the 
air below a red-heat, burning like tinder, and being thereby completely 
converted into ferric oxide. (Berxelius.) 

H. Hyposulphite of Ferrous Oxidb, or Ferrous Hyposulphite^ 
—Iron immersed in aqueous sulphurous acid and kept from contact of aiv 
dissolves without evolution of gaS| and forms sulphite and hyposulphite 
of ferrous oxide: 

8Fe + S80« = FcO, S0» + FcO, S«0«. 

The iron immediately becomes black and brittle by taking up sulphur^ 
(Berthollet, Ann, Chtm. 2, 58.) The iron dissolves completely with the 
exception of a few black flakes arising from impurities in the metal. 
(Fordos & Gelis, N. J. FharjrL 4, 333.) The sulphurous acid, in acting 
upon the iron, becomes first brown, then yellow, and afterwards trans- 
parent and colourless, the last change being attended with precipitation 
of sulphur; no hydrosulphuric acid is evolved, although the liquid contains 
a small quantity of that gas while it is in tlie yellow state, and therefore 
blackens paper moistened with acetate of lead. The resulting solution 
turns brown when heated, and yields a reddish precipitate; on the 
addition of hydrochloric acid, sulphurous acid is evolved and sulphur 
precipitated. The solution gives with alkalis and with ferrocyanide of 
potassium a white precipitate; with mercurous and mercuric salts, a black 
precipitate containing ^lobules of mercury; and with nitrate of silver, a 
white precipitate which afterwards blackens. (A. Vogel, J. pr. Chem, 
8, 102; vid, also Kone, Pogg. 63, 145.) — If very strong sulphurous acid is 
used, part of the ferrous sulphite crystallizes out spontaneously in the 
course of a few days, in white or greenish- white crystals. (Berthollet, 
A. Vogel.) By evaporating and cooling the solution out of contact of 
air, the greater part of the ferrous sulphite is separated out in the crys- 
talline form, and the mother-liquid when evaporated in vacuo (great care 
being taken to prevent ingress of air) yields crystals of the hyposulphite, 
which, however, are frequently contaminated with sulphur and green 
vitriol. For, in proportion as the air acts upon the colourless mother- 
liquid containing the ferrous hyposulphite, that liquid acquires a yellow 
colour from formation of ferric hyposulphite. During the subsequent 
evaporation, even in vacuo at ordinary temperatures, the ferric oxide 
converts the hyposulphurous acid into tetrathionic acid: 

Fe«0» + 2S«0« = 2FeO + S<0» ; 

and the tetrathionate of ferrous oxide thus produced is resolved by further 
evaporation into sulphur, sulphurous acid, and green vitriol: 

FeO, S<0» z= FcO, SO» + SO^ + 2S. 

(Fordos & O^lis.) IT Kdne separates the sulphite and hyposulphite of 
ferrous oxide obtained as above, by means of alcohol, in which the hypo- 
sulphite is easily soluble, while the sulphite is insoluble IT. By pre- 
cipitating green vitriol with hyposulphite of baryta, and evaporating the 
filtrate, green crystals are obtained, mixed with a basic salt of ferric 
oxide. (Rammelflberg, Pogg. 56, 806.) 



236 IKON. 

Besides the solable salt jast deeoribed, there likewise exists an 
insoluble hyposulphite of ferric oxide. When steel turnings (iron would 
probably act in the same way) are immersed for 14 days in a saturated 
aqueous solution of sulphurous acid contained in a closed vessel^ the 
transparent and colourless liquid poured off, and the black steel turnings 
washed with water, — small, translucent, greenish-white octohedrons are 
found adhering to their surfaces. These crystals do not fuse when 
heated, but evolv^e sulphurous acid together with a small quantity of 
sulphur: by exposure to the air, they become opaque and afterwards of a 
rust colour. With strong hydrochloric acid they effervesce violently, 
give off snlphurons acid gas, and form a yellow solution from which 
eulphur is deposited; their powder turns bbick when moistened with 
flolution of silver; they are insoluble in water, not even boiling water 
taking up a trace of iron; aqueous sulphurous acid dissolves them slowly. 
(A. Vogel.) 

I. SuLPHrrEOF Ferrous Oxioe, or Ferrous Sulphite. — The solution 
of iron in aqueous sulphurous acid formed out of contact of air (which 
likewise contains ferrous hyposulphite: vid. sup,) deposits, either imme- 
diately or when evaporated out of contact of air, crystals of ferrous sulphite, 
that salt separating out before the hyposulphite. (BerthoUet.) The solu- 
tion should be evaporated in vacuo, the crystals pressed between bibulous 
paper and then dried in vacuo. (Fordos & Gelis.) — When heated in a 
glass tube, they evolve sulphurous acid and water and leave a black 
residue. While yet moist, they oxidate in the air. They dissolve very 
sparin^y ia pure water, easily in aqueous sulphurous acid. This solution 
soon aoqutres a deep red colour by exposure to the air. (Fordos & (relis.) 

Crystallized, CalcuUtion, according to FordoB & GSis. 

FcO 35 37-23 

S02 32 34-04 

3H0 27 28-73 

FcO,SO« + 3Aq 94 10000 

K. Sulphite of Ferric Oxide, or Ferric Sulphite. — Freshly 
precipitated hydrate of ferric oxide dissolves readily in aqueous sulphurous 
acid, but the solution which is red at first, quickly becomes decolorized 
by formation of ferrous sulphate. The dry nydrate dissolves but very 
sparingly in cold sulphurous acid; the hot acid dissolves it quickly, but 
the solution consists of ferrous sulphate. — IT According to K5ne, if the 
excess of sulphurous acid be expelled by heat and the solution then left 
exposed to the air for several days, a red-brown precipitate is obtained, 
composed of Fe*0',S0*+7Aq. (Ann, Pkarm, 64, 241) 1.—2. Alkaline 
sulphites impart a deep red colour to ferric salts, even when largely 
diluted; but the mixture soon loses its colour even at ordinary tempera- 
tures, and immediately on the application of heat. (Berth ier, Ann. Chim. 
Phya. 50, 370; N. Ann. Chim. Phys. 7, 78.) 

L. Hyposulphatb op Ferrous Oxide, or Ferrous Htposulphate. 
— Formed by precipitating a solution of green vitriol by an exactly 
equivalent quantity of hyposulphate of baryta, and leaving the filtrate 
first to evaporate at a gentle heat and then to crystallize by spontaneous 
evaporation. — Oblique rhombic prisms, having the colour and taste of 
green vitriol. They become somewhat brown in the air by oxidation, but 
without further change. When carefully heated, (j^ey leave 49*05 per> 



FERROUS SULPHATE. 237 

cent, of dry ferrous sulphate. Very easily soluble in water, but not in 

alcohol; when the aqueous solution is boiled, the salt is converted into 
green vitriol. (Heeren.) 

Cryiialliied. Heeren. 

FeO 35 .... 23-03 2291 

S'O* 72 .... 47-37 4705 

5HO 45 .... 29-60 30-04 

FeO,S*0* + 5Aq 152 .... 100-00 ~. 100-00 

M. Hypobulphatb op Ferric Oxide, or Ferric Hyposulphatb.— * 
Octobasic. — Aqueous hyposulphuric acid dissolves but a rery small 
quantity of hydrated ferric oxide, even when freshly precipitated; it 
however combines with the oxide and forms a brown-red, very soft, easily 
suspended powder, which dries up to a brown, brittle mass having a 
conchoidal fracture and easOy soluble in hydrochloric acid. (Heeren.) 













Heeren. 


SFe^O* 


.... 624 


■ ••• 


71-23 


• ■•• 


69-99 


sw ..: 


72 


• »#• 


8-22 


»••• 


8-25 


20HO 


.... 180 


• ••• 


20-55 


• •■• 


21-76 


8Fe»O«S2O* + 20Aq. ... 


876 


• ••■ 


10000 


#••• 


100-00 



N. Sulphate of Ferrous Oxide, or Ferrous Sulphate. — iVofo- 
sulphate of Iron, Green Vitriol, Copperas. — This salt is formed in mines 
containing sulphide of iron, and dissolves in the water of the mine. — Dilute 
sulphuric acid dissolves iron with evolution of hydrogen gas. Strong oil of 
vitriol dissolves it slowly at ordinary temperatures with evolution of nydro- 
gen gas — more quickly when heated, and with evolution of sulphurous 
acid gas. Moist or heated sulphide of iron is converted by exposure to the 
air into green vitriol (pp. 229 and 234). — The crystallized salt is prepared 
on the small scale by dissolving iron in dilute sulphuric acid, filtering, eva- 
porating, and crystallizing. On the large scale, it is prepared in an impure 
state, by exposing native sulphide of iron to the action of the air-— or first 
roasting and then exposing it to the air, — and afterwards exhausting with 
water, evaporating, clarifying, and cooling. — ^When iron is immersed in 
mine- water containing sulphate of copper, the copper is precipitated, and a 
dilute solution of green vitriol is obtamed, which may be brought to the 
crystallizing point, first hy graduation, and afterwards by e vaporation. The 
commercial green- vitriol from Fahlnn and Dylta, and that also which is 
prepared in England, is crystallized from an acid solution, contains but 
little ferric sulphate, is of a greenish-blue colour, and often covered with a 
white or yellow powder. The German green-vitriol, which is crystallized 
from a more neutral solution, and contains but a small quantity of ferric 
salt, is of a dirty green colour and dry. That from Moscow is crystallized 
from a solution containing a considerable quantity of ferric salt, and 
is therefore mixed with that salt; it has a grass-green colour and 
unctuous aspect, because it remains moist; it also reddens litmus strongly. 
(Bonsdorff.) — Besides ferric sulphate, commercial green yitriol may 
also contain protoxide of copper, oxide of zinc, binoxide of tin, prot- 
oxide of manganese, alumina, magnesia, and lime in the state of sul- 
phates, and likewise arsenious acid. — The cupric and ferric oxides may 
DO separated by mixing the aqueous solution with a small quantity of 
sulphuric acid and digesting It with metallic iron out of contact of air; 
and the arsenic, copper, and tin, by saturating the solution with sul- 
phuretted hydrogen, setting it aside /or two days, and then warming and 
filtering. 



238 IRON. 

In conseqnence of tlie great facility with wliicli ferrons Bal{>batd 
absorbs oxygen from the air^ the crystals are very apt to become contar 
minated with ferric sulphate. Green vitriol free from ferric oxide may 
be obtained by the following processes : 1 . By saturating dilute sulphuric 
acid with iron^ boiling the liquid with iron-filings in a narrow-necked 
flask, till the crystallizing point is attained, and straining it through a 
filter moistened with water, into a vessel rinsed out with a little dilute 
sulphuric acid. The sulphuric acid prevents the filtrate from becoming 
turbid. The funnel must have a very long neck reaching to the bottom 
of the vessel. The crystals, as they form, are left to drain upon a 
funnel, then roiled backwards and forwards between bibulous paper, till 
they no longer wet it, and dried upon paper at a temperature not exceed- 
ing 30^ When well dried, they remain permanent for a long time 
in dry air, and for a tolerably long time m damp air. {v. Bonsdorfi, 
Pogg. 31, 81.) — 2. By dissolving 200 parts of iron-filings in 2,400 of 
water, to which 300 of oil of vitriol is gradually added, evaporating the 
liquid to the crystallizing point in a cast-iron vessel ; mixing it with 15 
parts of oil of vitriol; filtering hot; cooling; pressing the crystals to 
powder as soon as they are formed ; washing with alcohol, and quickly 
drying the bluish-white powder between bibulous paper. (Gieseler, y. Br, 
Arch. 27, 193.) — 3. By leaving good green vitriol to crystallize from 
water acidulated with sulphuric acid ; boiling 500 parts of the resulting 
crystals, for a while, with 550 parts of water and 8 parts of iron-turnings, 
and filtering the solution at a boiling heat into a vessel containing a 
mixture of 375 pts. alcohol of 36° B., and 8 parts of oil of vitriol, the 
mixture being stirred all the while. After cooling, the mother-liquid is 
strained off from the small crystals which form, the crystals drained upon 
linen, and then dried between bibulous paper frequently renewed. The 
alcohol retains in solution the whole of the ferric salt, the solubility of 
that salt being increased by the free sulphuric acid. The crystals contain 
their full amount of water. (Berthemot, J. Pharm. 25, 206.) 

By heating the crystals out of contact of air, the anhydrous salt is 
obtained in the form of a white, harsh powder. — This when heated in a 
retort, gives off sulphurous acid gas, and is converted into a compound of 
1 At. ferric oxide and 1 At. sulphuric acid : 

2(FcO, S0>) « Fe»0', SO» + SO*. 

At a still higher temperature, the rest of the sulphuric acid is given ofi^ 
and red ferric oxide left behind. Part of the acid distils over nndeoom- 
posed, and may be condensed in the form of anhydrous acid in a receiver 
kept at a very low temperature ; the rest passes over a« a mixture of 
1 vol. oxygen, and 2 vol. sulphurons acid giu. (Bassy.) — ^When mode- 
rately heated in an open vessel and stirred, it is converted — the ferrous 
oxide taking up oxygen from the air — into yellowish-brown burtU or 
calcined green vitriol, containing 1 At. ferric oxide and 2 At. sulphuric 
acid. Complete conversion into ferric salt is unattainable; as soon as all 
the protoxide is converted into sesquioxide, sulphuric acid is given off^ 
and colcothar remains behind. (Waltl, Repert, 41, 428.) Dry ferrous 
sulphate gently ignited with charcoal in a retort, gives off about 78 
volumes of sulphurous acid gas to 22 vol. carbonic acid, and leaves ferrie 
oxide free from sulphide of iron, (Gay-Lussac, Ann* Chitn. Phy9^ 
63, 433; also /. pr. Chent. 11, 67.) 



FERROUS SULPHATE* 2S9 



» 


35 


• ■•• 


46-66 
53-33 


•••• 


47-07 
52-93 


••ft 

• ••• 


42-17 


so» 


40 


57-83 



FeO,SO» 75 .... 100-00 .... lOO'OO .... 100-00 

Combinations vfith Water. — The dehydiated flalt recorers its 7 atomB 
of water by exposore to moist air. (Braudes, Sckto. 51, 438.) — «. Mono* 
hydratecL — Remains when the hepta-hyd rated salt is heated to 140^ in 
vacuo ; contains 1 atom of water in a state of intimate combination, but 
gives it up at a temperature above 280^ (between 200° and 300°, Mits- 
cherlich, Fogg, 18, 152), and by careful heating maybe freed from it 
without loss of acid. (Graham, Phil. Mag. J. 3, 421.) 

fi. Bihydrated, — When oil of vitriol is slowly added to a saturated 
solution of ferrous sulphate — ^so as not to produce any considerable rise of 
temperature — till the mixture attains a specific gravity of 1 '33, and the 
liquid then left to evaporate over oil of vitriol in a receiver not exhausted 
of air, the hepta-hydrated salt separates out first; then, when \ of the 
liquid are evaporated, a salt containing 4 atoms of water; then sesqui- 
sulphate of ferrous oxide (p. 242); and lastly, the bihydrated salt in the 
form of a dark green, crystallo-granular mass. (v. Bonsdorff, Ber. iiber d, 
Vermmml. d. deutschen Naturf. in Prag. 124.) 

y, Ter-hydraUd. — The solution of green vitriol in hot hydrochlorie 
acid, yields on cooling, p&ftly crystals of the hepta-hydrated, and partly 
of the ter-hydrated salt. The latter are translucent, of a much paler 
green colour, and harder than the former; when dissolved in water, they 
again yield ordinary green vitriol. (Kane, Ann. Phami. 19, 7.) — On 
evaporating a solution of green vitriol mixed with a large quantity of 
sulphuric acid, the ter-hydrated salt is obtained in the form of a white 
solid crust. (Kiihn, Schw. 61, 235.) 









Kane. 




Ktihn. 


FeO 


35 


>••. d4 tJ X ••. 


33-4 


••■t 


34-3 


S0» 


40 


• •«. Vi3* t»£ •>• 


37-4 


• ••■ 


390 


3H0 


27 


.... 26-47 


29-2 


• •«• 


26-7 


FeO,S05 + 3Aq. 


102 


.... 10000 


1000 


• ■•■ 


100*0 



h. Tetra-hydrated. — 1. By the process described under ^, this salt is 
obtained in crystals having the ^een colour of Chrysoprase. (Bonsdorff.) 
— 2. It ciystailizes on evaporating a solution of green vitriol at 80°, and 
corresponds to the tetra-hydrated sulphate of manganous oxide. (IV., 222.) 
Regnault. (N. Ann. Chim. Phys. 1,201.) 

c. Ilepta-hydrated.'^ThiB is the common green vitriol.*— Pale green- 
ish-blue, translucent crystals, belonging to the oblique prismatic system. 
Fig. Ill and other fonms^ i : t* or tt'=99° 2'; « : n'=82° 20'; i : « =2 
153*^; t:/3=123^55'; t:c=159^; »:rf=136M0'; t:/=119^15'. (Wol- 
laston, Schtp. 24, 102; Brooke, Ann. Phil. 22, 120; G. Rose, Pogg. 7, 
239.) Yields a white powder; scarcely reddens litmus, and only when 
the air has access to it, the effect being then doe to the formation of a 
ferric salt (Bonsdorff.) 

Thorn- Mitsch- 
tton. erlich. 





Ber- Berg- Kir- 




teWxxB. man. wan. 


FeO 


35 .... 25*36 .... 25-7 .... 23 .... 28 


SO» 


40 .... 28-98 .... 28-9 .... 39 .... 26 


7H0 


63 .... 45-66 .... 45-4 .... 38 .... 46 



28-31 
-26-7) ••*• 



56-08 
450 .... 43-92 



PeO,SO*+7Aq. 138 ....lOO'OO .... 100-0 .... 100 .... 100 .... 100-0 .... 10000 



240 IRON. 

The cr]r8tal8 fase in their water of oryBtallization when heated; and 
if the air l>e exeladed, leave the white anhydrous salt. When exposed to 
the air between 40^ and 50^ they effloresce through and through to a 
white mass (Bonsdorff); oil of vitriol and alcohol likewise withdraw 
their water and cause them to turn white. At ordinary temperatures, 
they oxidize and turn brown, in proportion as they have been less com- 

gletely dried, as the air is moister, and as the solution from which they 
ave been formed is more neutral. Crystals obtained from an acid solu- 
tion are permanent in air which is not very damp ; but if they are kept 
under a bell -jar containing air, and closed with water at the bottom, their 
surface turns yellowish -brown in the course of a few months, a portion of 
the salt being at the same time dissolved by the water which is deposited. 
Crystals deposited from a perfectly neutral solution, assume a dingy 
green colour when exposed to the air even for a few days, the colour 
continually becoming darker ; under a bell-jar standing in water, they 
deliquesce more rapidly and soon turn brown. The powder of crystals 
obtained from an acid solution turns yellowish-green after a few weeks* 
exposure to the air. 

1 part of the crystals dissolves in 1 '6 parts of cold, and in 0*3 of boil- 
ing water. At 10** in 164 parts; at 15^ in 1-43; at 24° in 087; at 
33^ in 0-66; at 46^ in 044; at 60^ in 038; at 84° in 0-37; at 90" in. 
0-27; and at 100^ in 0*3 parts of water. (Brandos & Fimhaber. Br. 
Arch. 7, 83.) — The solution has a pale greenish-blue colour. Alcohol and 
oil of vitriol precipitate from it the white, partly dehydrated salt. Glacial 
acetic acid likewise precipitates the salt undecoraposed from the solution, 
60 that not a trace of iron is left in the liquid. (Persoz, Ohim, mol^cuL 
346.) The solution becomes turbid when exposed to the air, yellowish- 
brown disulphate of ferric oxi^.e being precipitated, and tersulphate being 
dissolved and forming a brown solution; 

10(FeO, S0«) + 50 = 2Pc«0«, SO» + 3( FeW, 3S0*). 

On the addition of sal-ammoniac, a solution is formed, consisting of sul- 
phate and hydrochlorate of ferrous oxide and ammonia. (A. Yogel, «/*. 
pr. Chem. 2, 192.) 

A solution of green vitriol absorbs nitric oxide gas, forming a dark 
greenish-brown liquid, which contains 1 at. nitric oxide to 4 at. oil 
of vitriol. The solution of 300 pts. (1 at.) of dry ferrous sulphate, 
absorbs 28*5 pts. (therefore not quite 1 at., which would weigh 30) of 
nitric oxide. If the sulphuric acid is in excess, the same quantity of 
nitric oxide gas is absorbed, and produces the same colour. (Peligot.)-^ 
The liquid contains ferrous sulphate and nitric oxide in the unaltered 
state ; the latter may be driven off in vacuo, or by the application of 
heat; but in the latter case, a small portion of the nitric oxide gives op 
oxygen to the ferrous oxide, so that the evolution of nitric oxide is 
accompanied by the conversion of a small portion of ferrous salt into 
ferric salt. If the liouid be placed, tofi;ether with chloride of calcium, 
under a bell-jar filled with nitric oxide gas, ferric salt is formed and 
nitric oxide decomposed, as soon as the solution becomes somewhat con- 
centrated. — An alkali added to the liquid produces a greyish-white pre- 
cipitate, probably a compound of hydrated ferrous oxide with nitrio 
oxide, which, however, soon gives off gas, turns bluish-green, and 
afterwards yellow. No salt of nitric or of nitrous acid is formed in this 
action. — Phosphate of soda forms a reddish-brown precipitate, which 
contains nitric oxide in a state of combination, and, when exposed to the 



FERROUS SULPHATE. 241 

aify turns white and yields phosphate of ferric oxide. In a similar 
manner, ferrocyanide of potassium forms red-brown flakes, which contain 
nitric oxide and immediately turn blue in the air. (Peligot, Ann. Chim. 
Pkys, 54, 17; also J, Fharm. 19, 644; also Schw, 69, 341; also Ann, 
Pharm, 9, 259.) — According to Sir H. Davy, 100 parts of green vitriol 
solution, of sp. gr. 1*4, absorb 0*63 nitric oxide, three-fourths of which 
remains unaltered, but the remaining fourth decomposes a portion of the 
water, and forms ammonia, nitric acid [1], and ferric oxide; a small 
quantity of nitrogen is likewise absorbed together with the nitric oxide, 
and is also converted into ammonia. The remaining three-fonrths of 
nndecomposed nitric oxide may be expelled from the liquid by heat. 
(Humboldt & Vauquelin, Scher, J, 3, 81.) 

The compound of green vitriol with nitric oxide imparts a purple-red 
colour to large quantities of oil of vitriol, provided no rise of temperature 
takes place. Oil of vitriol, to which a small quantity of ferrous sulphate 
bas been added, acquires a rose-red colour by absorbing small quantities 
of nitric oxide, and a deep purple-red if it absorbs a larger quantity. 
The same red mixture is obtained when oil of vitriol containing nitric 
oxide, nitrous or nitric acid, or a nitrate, is mixed with powdered green 
vitriol or its aqueous solution, slowly enough to prevent rise of tempera- 
ture. Upon this character is founded the detection of those oxides of 
nitrogen in oil of vitriol (II. 181), and that of traces of nitrites and 
nitrates. (II. 401; Desbassins de Richemont, J. Chim, mSd. 11, 504.)—^ 
Bussy & Lecann («/. Fharm, 11, 341 ; also Schw, 46, 368), by dissolving 
ferrous sulphate in oil of vitriol, obtained a red liquid which they regarded 
as an acid sulphate of ferrous oxide. Their sulphuric acid evidently con- 
tained nitric oxide. When an aqueous solution of ferrous sulphate 
saturated with nitric oxide, is slowly mixed with oil of vitriol, the 
greenish-brown colour likewise changes to red. (Jacquelin, N, Ann, 
Chim. Fhys. 7, 1 96.) 

The red liquid loses its colour when heated, giving off sulphurous acid, 
and precipitating white tersulphate of ferric oxide. Water carefully 
added, so as not to occasion rise of temperature, gradually dilutes the 
colour, till it finally becomes imperceptible. (Bussy & Lecann.) Water 
decolorizes the solution, after first turning it brown and yellow. (Des- 
bassins.) Compounds which convert the ferrous oxide into ferric oxide, 
destroy the colour, and produce a white cloud, proceeding from tersulphate 
of ferric oxide. Such iff the action produced by nitric and its salts, the 
native oxides of manganese (Brauntttein), peroxide of manganese (Bussy 
& Lecann); as also by hyponitric acid and sulphate of manganic oxide, 
but not by nitrites. (Desbassins.) 

Sulphate of ferrous oxide is capable of uniting in nearly all proportions 
with sulphate of zinc-oxide or sulphate of cupric oxide, forming a double 
salt, of the form of green vitriol 

Sesqumdphate of Ferrotu Oxide ? — (For the preparation of this salt, 
see page 238, /3.) Colourless crystals, having a laminar texture like that 
of gypsum, nearly tasteless, sparingly soluble in water ; contain 28*38 
p. c. ferrous oxide, 45*42 acid, and 25*97 water — ^loss 0*33. (Bonsdorff.) 
Their composition may be nearly represented by 2FeO,3SO'+7Aq. 

P. StTLPHATE OF Ferric Oxide. — a, Sexhastc-^FoTmed by the 
weathering of iron pyrites in alum-slate. Dark brown ; massive ; has 
a fatty lustre; yielcls a brownish-yellow powder, and is insoluble in 

VOL. v. B 



342 IRON. 

water, bat slowly solable in heated hydrocUoric aoid. (Th. Scheerer, 

Fogg. 45, 188.) 

Afproximaie eakulatkm* Scheerer. 

6Pe*0» 468 .... 7826 8073 

SO» 40 .... 6-70 600 

lOHO 90 .... 1504 13-57 

6FeH)*,BO>+10Aq..... 598 .... 10000 ^ 100*30 

According to Scheerer, it is 2(7Fe*0»,SO') + 14Aq. 

5. Qtiadrobasic. — ^When tersolphate of ferric oxide is precipitated hj 
acetate of baryta, and the remainder of the sulphuric acid removed from 
the filtrate by a small quantity of baryta- water, light-brown flakes are 
thrown down, together with the sulphate of baryta, and may be separated 
from it by levigation; they contain 88*62 per cent, of ferric oxide and 
11*38 of sulphuric acid. (Anthon, Repert. 81, 237.) 

c. Terbasic or Tristdpkate, — Precipitated, on boiling a dilute solution 
of tersulphate of ferric oxide, even when the latter contains sulphate of 
potash. After drying at 100°, it is a light powder of a deep orange- 
yellow colour, that colour being lighter, however, as the solution from 
which the salt is precipitated is more dilute. It loses its water below a 
red heat, and turns dark brown; at a red heat, it leaves ferric oxide. It 
is insoluble in water, but dissolves with tolerable facility in acids. (Th. 

Scheerer, Pogg. 44, 453.) 

Scheerer. 

3Fe»0» 234 .... 75*49 74*43 

SO» 40 .... 12*90 12-69 

4HO 36 .... 11*61 12*80 

3Fe30»,SO' + 4Aq iliS Z 10000 ~, 99*92 

According to Scheerer, it is 2(3Fe'0»,S03) + 9Aq. 

d. Bibasic or DisuIpJiaie, — Occurs native, combined with 6 atoms of 
water, in the form of Vitriol-ochre. Precipitated in the hyd rated state on 
mixing the tersulphate with a quantity of ammonia not sufficient for its 
complete decomposition; also when an aqueous solution of green vitriol 
is exposed to the air. It is consequently deposited in vitriol and alum 
works by the action of the air on the mother-liquid of the vitriol or alum; 
the deposit is called " the cream" (Schmand), Yellowish-brown. Gives 
off its water when heated, and assumes a brown-red colour : when some- 
what strongly ignited, it gives off undecomposed sulphuric acid. (Berzo- 
lius, Gilb. 40, 293.) 

Anhydrma. Berxelii^. Thomson. 

2Fe203 156 .... 79*59 798 .... 80 

SO» 40 .... 20*41 20*2 .... 20 

2Fe20»,SO« 196 .... 10000 ZZ 100*0 Z 100* 

HydraM. Berzelius. Soubeiran. 

2F<^0» 156 .... 62-4 624 .... 590 

SO» 40 .... 16*0 15*9 .... 11-5 

6H0 54 .... 21*6 21*7 .... 29*5 



2Fe«03,S03 + 6Aq. 250 .... 1000 100*0 .... 1000 

The salt examined by Soubeiran was obtained by precipitating the tersul- 
phate of ferric oxide with carbonate of potash in the cold. 

% According to Wittstein, the precipitate deposited from a solatioB 



FERRIC SULPHATE. 243 

of green vitriol exposed to the air conBifito, after being dried at 100°, of 
aesquisulphate of ferric oxide, 2Fe'0',dS0' + 8 Aq., and not of disulphate, 
as stated by Beraelius. (Eepert. Fkarm. 3rd series, 1, 185.) IT 

An ocbrey stalactite from the alum-slate quarry at Gemsdorf, havii^g 
the form of a crust, of sp. gr. \'%f and pale yeUowish-grey colour, was 
found to contain 40*06 p. c. ferric oxide, 6*80 alumina, 11*90 sulphuric 
acid, 40*13 water, and 0*11 matrix; these numbers give rather more than 
2 atoms of base (ferric oxide and alumina together) and 15 atoms of 
waler to 1 atom of sulphuric acid. (Breithaupt & Erdmann, Scfvw, 62, 
104.) 

e. JfonomiphaU. — Formed by adding carbonate of potash to tersni- 
phate of ferric oxide as long as the alkali does not occasion permanent 
turbidity, — ^and heating the resulting red liquid till th^ salt separates out. 
Light reddish-yellow powder. (Soubeiran, Ann. Chim. Phy$, 44, 329; 
also J. Pharm, 16, 525.) 

Soubeiran. 

Fe»0« 78 .... 53*79 &5*5 

S03 40 .... 27*59 25*5 

3HO 27 .... 18-62 19*0 

Fe=0»,S0» + 3Aq 145 .... 10000 1000 

/. Sesquuulphate, — FibroferrUe. — Warty; separates in scales; fibrous 
in a direction perpendicular to the surface of separation; specific gravity, 
about 2'5 ; pale greenish* grey; powder yellowish ; fibres translucent. 
Tastes somewhat rough and sour. When heated, it evolves a large 
quantity of water with a small quantity of sulphur (inasmuch as the 
mineral contains 10 per cent, of earthy matter and sulphur), the fibres 
separating at the same time, and assuming an oraogo-yellow colour. On 
charcoal before the blowpipe, it decrepitates violently; emits an odour of 
sulphur, and leaves ferric oxide. In cold water, it splits into fibres, a 
small quantity being partially dissolved. Boiling-water takes up rather 
more, and colours the fibres orange-yellow. In hydrochloric acid it swells 
up like a sponge; acquires a bright orange-yellow colour, and soon dis- 
solves with the exception of the sulphur and the earthy portiona. 
(Prideaux, Phil Mag. J. 18, 397; also J. pr. Chem. 24, 127.J 

2Fe«08 156 .... 

3S03 120 .... 

18HO 162 .... 

Earthy matter. Sulphur, ) «a 

andloif I •"' •••• *" 

2F^O»,3SO»+18Aq 438 .... 10000 Z, 100 100-00 

g, BUtdfAaie. — If to a tolerably concentrated solution of tersulphate 
of ferric oxide, hydrate or carbonate of lime be added till the precipitate 
no longer re-dissoWes, and the liquid be rapidly filtered, the dark brown 
filtrate contains the bisulphate. This salt may likewise be obtained by 
agitating a concentrated solution of the tersulphate with the disulphate 
precipitated in the cold (that which is precipitated from a hot solution 
will not dissolve). The quantity of disulphate thus dissolved is not, 
however, sufiicient to convert the whole of the tersulphate into bisulphate. 
The yellow deposit formed on crystals of green vitriol exposed to the 
air consists of this same salt ; hence the solution in cold water of green 
vitriol thus altered deposits a large quantity of disulphate when heated* 

The solution of the bisulphate, when abandoned to spontaneous eva- 

r2 





Prideaux. 


On 


35-62 


.••« Ox p..« 


34-44 


27-40 


• a.. *0 .... 


28-89 


36-98 


.... oo .... 


36*67 



244 IRON* 

poration, leaves a gammy, yellowish-brown mass. Whca left to itself, 
it is partly resolved into disulphate which is precipitated, and tersulphate 
which remains in solution; the decomposition is, however, less complete 
as the solution is more concentrated. For complete decomposition, a 
boiling heat is necessary. This salt forms double salts with the sulphates 
of potash and ammonia, and expels the tersulphate of ferric oxide from 
its combinations with these alkaline sulphates. (Maus, Pogg, 11^ 77.) 

Maus. 

Fe203 78 .... 49-37 49*9 

2S0' 80 .... 50-63 50-1 

Fc»0», 2S0».. 158 .... 100-00 ZZ 1000 

To this head belongs an iron ore from the province of Coqnimbo, in 
Chili, which occurs in globular deposits of a dingy yellow-ffreen colour, 

a lustre, and excentrically fibrous texture. Cold water decomposes it 
lally, boiling water more quickly, with separation of ferric oxide [or 
phate 1]. (H. Rose, Fogg. 27, 310.) 



Fc^O* 


78 
80 
90 




31-45 
32-26 
36-29 


«. .. 


H.Rose. 

2811 

27-82 

33-48 

5-86 

3-63 

1-43 


• •■a 


Or: 
31-44 


2S0» 


31-12 


lOHO 

CaO,SO» + 2Aq 

MgO,SO* + 7Aq 

SiO* 


37-44 


Fe»O»,2BO»+10Aq. 


248 




100-00 


.... 


100-33 


• «.. 


10000 



A nother ore, from the same locality, occurring in thin six-sided tables, 
or granular, yellow, and translucent, contains more than 2 and less than 
3 atoms of sulphuric acid to 1 atom of ferric oxide, viz. 2*64 d. c. mag- 
nesia; 26*11 ferric oxide; 1*95 alumina; 39*60 sulphuric acid; 29*67 
water; and 1 '37 silica. (H. Rose.) 

A. ^er«u^Aato.^The so-callea Neutral Svlphate of Ferric OxicU,-^ 
A solution of green vitriol, exposed to the air, or boiled with nitric acid 
and freed from that acid by repeated solution and evaporation to dryness, 
is resolved into disulphate of ferric oxide and soluble tersulphate. If the 
solution of the ferrous sulphate is previously mixed with half as much 
sulphuric acid as it already contains, it is wholly converted into ferric 
tersulphate. The same solution is obtained by treating one of the more basic 
salts, or the ferric oxide itself, with dilute sulphuric acid, or by treating iron 
filings or ferrous sulphate with excess of oil of vitriol till the excess is eva- 
porated, and then dissolving in water. 30 lb. of hydrated ferric oxide, 701b. 
of red oxide, and 150 lb. oil of vitriol, heated in an iron vessel, rise to a 
brifi;ht red heat, with evolution of sulphuric acid, vapour being evolved, 
and portions of the mass projected out of the vessel. (Priickuer, ^cAtr. 
66, 296.) The yellowish-brown liquid, which strongly reddens litmus, 
is converted by evaporation into a brownish-yellow syrup; and this, 
when kept for some time, solidifies into a partly pale yellow, partly 
white mass of indistinct crystals. The colourless, regular octohedrons 
obtained from the solution by Hausmann and Sylvester (Ann, Phil. 13, 
298 & 460) probably consisted of ammonia iron-alum or potash iron-alum. 
On further evaporation, there remains a brown resinous mass, which, when 
completely deprived of its water, is converted into the dirty-white anhy- 
drous salt. The resinous mass is difiicult to dry ; but if mixed with 

kter while still hot^ it solidifies suddeulyi and may then be easily dried 



F£RRIC SULPHATB. 246 

at a gentle heat. (Wittstein, ReperL 63, 223.) The anhydrous salt is a 
white powder, which dissolves slowly, and consequently ha^ but a very 
slight taste; in the state of solution, however, it tastes strongly ferruginous. 
When somewhat strongly heated, it gives off anhydrous sulphuric acid. 
It slowly absorbs moisture from the air, and ultimately deliquesces to a 
brown liquid. It is perfectly insoluble in strong oil of vitriol, by which, 
indeed, it is precipitated from the concentrated aqueous solution in the 
form of the white dehydrated salt. The concentrated aqueous solution 
does not become turbid on boiling; but the more dilute it is, the more 
turbid does it become, and the lower is the temperature required to 
produce the turbidity; the deposit consists of the terbasic salt. The 
solution of 1 pt. of the salt in 100 water begins to show turbidity at 95^, 
and deposits, on boiling, about one-third of its ferric oxide in the form of 
iersulphate; with 200 parts of water, these numbers are 70^ and ^; with 
400 water, 59^ and J; with 800 water, 50 and |; with 1000 water, 47-5 
and -^. (Th. Scheerer, Pogg, 44, 453.) When the solution is digested 
with iron filings, ferrous sulphate is produced; hydrogen ^as is, however^ 
evolved at the same time, and a basic salt of ferric oxide precipitated. 
(Berzelius.) On boiling the solution with silver, sulphate of ferrous oxide 
and sulphate of silver-oxide are produced; but as the liquid cools^ the 
silver is again precipitated and the ferric salt reproduced. {Sch, 94.) 
The solution mixed with common salt evolves hydrochloric acid at 60^; 
and if it be evaporated to dryness, and the residue further heated with 
access of air, chlorine is given off, and sulphate of soda, together with 
free ferric oxide, left behind. (Schaffhautl, Ann. Fharm, 43^ 28.) The 
salt is likewise soluble in alcohol. 

Thomson^ 
Bussy & Lecann. 

Fe»0» 78 .... 39-39 • 40 

380^ 120 .... 60-61 60 

Fe»03,3S03 198 .... 10000 ~. 100 

Coquimhite. — Found together with the two ores of iron described on 
page 244. Fig, 137; r : o-=151^; cleavage imperfect, parallel to r and <r; 
fracture conchoidal; colour violet- white. It appears to have been produced 
by the weathering of iron pyrites. It dissolves in hydrochloric acid, or 
in cold water, with the exception of the silica; the latter solution deposits 
a large quantity of ferric oxide on boiling; when left to itself at ordinary 
temperatures, it yields indistinct crystals. (H. Rose, Fogg. 27> 310.) 

H. Rose, Or : 



Fe»03 


78 




27-08 


2411 


•tti 


25*24 


Al^QS 






■••• 


0-92 


•••• 


0-96 


3SO« 


120 




41-67 


41-87 


■ ••• 


43-84 


lOHO 


90 




31-25 


28-62 


•••• 


29-96 


CaO,SO« + 2Aq 






• •«• 


2-24 






M-0,S03 + 7Aq 






••■fl 


1-97 






Si()« 






«■«■ 


0-31 







Fe=03,3S03 + lOAq. 288 .... 10000 100*04 .... 100-00 

Q. Ferrous Sulphocarbonate. — An aqueous solution of sulpho- 
carbonate of calcium yields, with ferrous salts, a clear mixture of a deep 
wine-red colour, which gradually becomes darker, and ultimately forms a 
liquid which appears ink-black by reflected light ; when the ferrous salt 
is in excess, part of the compound is deposited in the form of a black 
powder. (Berzelius.) 



S4B iftOK. 

R. Fjsrrio Sitlphocarbonatb.— Ferric salts yield, with aqneoHs enl- 
phocarbonate of calciam, a deep red precipitate, which retains its colonr 
when dry, and yields an nmber-brown powder. When gently heated, it 
gives off first bisulphide of carbon, then sulphur, and leaves protosulpfaide 
of iron. It is insoluble in water. (Berzelius.) 

S. Ferrous HTl^strLPHoPHosPHrfB. — FeS, PS. Artificial ^-sul- 
pbide of iron finely pulverized and heated with protosnlphide of phos- 
phorus in a bulb-tube (p. 20), through which a current of hydrogen gas 
IS passed, takes up the sulphide of phosphorus with avidity, and the 
deep yellow colonr of the powder is thereby converted into black. The 
product is FeS,P8, contaminated with a small quantity of 2FeS,PS'. 
(BerzeliQS.) 

T. Fbrroits Sulphophosphitb.— 2FeS,P6'. Obtained by heating 
pulrerised iron pyrites in the same manner with protosnlphide of phos* 
phorus; combination takes place, attended with powerful evolution of heat 
After the excess of protosnlphide of phosphorus has been distilled off^ 
there remains a lump reddened externally by a deposit of P'S,PS, deep 
yellow within, with a faint metallic lustre, and somewhat granular. The 
compound, when distilled, leaves 2FeS,PS in the form of a black-brown 
residue, which is not decomposed by hydrochloric acid, but ouly by boiling 
aqmn-regia. The undecomposed compound is likewise insoluble in boilini^ 
hydroeuoTic acid. In damp air it is slowly decomposed, emitting a faint 
odoor of sulphuretted hydn^o^en. (Benselius, Ann, Fharm. 46, 256.) 



2Ps 

P..:. 



..•• !•.«..•• 









Berzelius. 


54-0 .... 


32-65 




33-90 


»1*4 .... 


18-98 


.....•.• 


18-12 


80-0 .... 


48-37 




47-98 



tnSt?& .... 165*4 .... 100-00 10000 

U. PhobpBositlphatb op Fbrric Oxidb.— •i>MKi<>cAt^e. Resembles 
iron-cinder in outward appearance; kidney-shaped or stalactitic; sepaftttes 
in Bcaies ; fracture conchoidal ; brownish-yellow, somewhat translucent ; 
colours the blowpipe flame green, and fuses at the edges, with some intu- 
mescence, to a black, slightly magnetic enamel. (Breithaupt, J.pr, Chem, 
10, 503; Plattner, RammeUkerg. Handw'drterb, d» Min. Snppl. 1, 45.) 
Boiling-water extracts from the pulverized mineral 12*6 p. c. sulphuric 
acid, without any ferric oxide; 2*3 p. c. acid remains behind. (Rammels- 
berg, loc. <fH,) It appears to be: (Fe»0',2PO«+8Aq.)+4(Fe*O*,SO' 
+6Aq). 

DiadotkUe. Flattner. 

5Fe»0» 3900 .... 3977 39*69 

2PO«. 142-8 .... 14-56 14-81 

4S0» 1600 .... 16-31 1515 

32HO 288-0 .... 29*36 30*35 

980-8 ..>. 100-00 ZT] 100-00 



Iron and Sblbnutk. 

A. Sblbnibb of Iron.— -Vapours of selenium passed over heated 
iron filings combine therewith, producing considerable evolution of light 
and heat; when iron filings are heated with pulveriied selenium, partial 



PROTIODIDB OF IRON. 247 

combination takes place, unattended with visible combustion. Yellowish- 
grey, with metallic lustre; hard, brittle, with granular fracture; when 
heated alone, it does not fuse, but merely bakes together. Fuses before 
the blowpipe, giving off suboxide of selenium, and forming a black, 
brittle globule, which has a conchoidal fracture, and appears to consist 
of ferrous selenite. Dissolves in hydrochloric acid, with evolution of 
seleniuretted hydrogen gas. If the hydrochloric acid contains air, or if 
the air has access to the liquid, a red cloud is formed, arising from the 
separation of selenium; at the same time there is evolved another gas 
which has a very disagreeable odour, is not absorbed by water or by 
aqueous alkalis^ and gi?es a black precipitate with nitrate ^of mercurous 
oxide. 

Pounded selenide of iron, when heated with free selenium, takes up 
an additional quantity, and is converted into a brownish powder, which is 
insoluble in hydrochloric acid, and gives off the excess of selenium at a 
strong red heat. (Berzelius.) 

B. Sblenitb of Ferrous Oxidb, or Ferrous Selenite. — Iron is 
scarcely attacked by selenions acid, but becomes covered with a copper- 
coloured film of selenium. — a. Monoselenvte. Formed by double affinity. 
White precipitate, which, when exposed to the air, first turns grey, and 
then yellow. When freshly precipitated, it dissolves in hydrochloric 
acid — ^the solution containing ferric oxide and selenions acid, and a portion 
of the selenium being separated. 

h, Biselenite, — By dissolving a in selenious acid, from which, how- 
ever, it is soon deposited. Slightly soluble in water; the solution, when 
heated, yields a brown precipitate^ which is a mixture of selenium and 
ferric selenite. (Berzelius.) 

C. Selbnitb op Ferric Oxide, or Ferric Selenite.— a. Sesqui- 
selenite, — By digesting 5 or c in ammonia. Does not dissolve in water, 
but passes with it through the filter. Contains about 48 ferric oxide to 
52 acid; the latter is completely evolved on the application of heat. 

b, TerseUnUe, — By double decomposition. White powder, becoming 
somewhat yellowish when dry. When heated, it gives off water, turns 
red, and loses all its acid. According to Muspratt, it contains 4 atoms of 
water. 

<?. SexieleniU, — When iron is dissolved in excess of a mixture of 
boiling nitric acid and selenious acid, this salt crystallizes on cooling in 
pistacoio-green laminsB, which give off their water and turn black when 
heated, afterwards become red on cooling, and give off all their selenious 
acid, leaving sesquioxide of iron. It is insoluble in water, but dissolves 
in hydrochloric acid^ forming an orange-yellow solution. (Berzelius.) 



Iron and Iodine. 

A. Protiodidb of Iron, or Ferrous Iodide.-— 1. The two substances 
nnite readily, with slight evolution of heat^ and form a brown mass 
which fuses at a red-heat and volatilizes at a higher temperature. 
(Guy-Lussac, H. Davy.) — 2. SemUas, by passing iodine vapour and 
vapour of water through a red-hot gun-barrel containing charcoal, ob- 
tained highly lustrous crystals which looked like gold filings and contained 
iodine and iron.--d. When 1 part of iron is digested in water with 2 parts 



248 IRON. 

of iodine and the resulting aqneons iodide of iron boiled down in a glass 
flask in which an iron wire is placed, a steel-grey mass is obtained, having 
a laminar fracture, fusing at 177^, of sharp and astringent taste, and 
smelling of iodine while yet moist. When strongly heated in the air, it 
gives off iodine in vapour^ and is converted into ferric oxide. (Todd 
I'homson.) 

Hydnited FrUiodide of Iron, or ffydriodcUe of Ferrous 0«ufe.— The 
aqueous solution evaporated in the water-bath yields dark greenish-brown 
rhombic crystals, which, when strongly heated in the air, ^ve off water 
and iodine and leave sesquiozide of iron. (J. D. Smith, PhiL Mag, J. 7, 
156; also N, Br. Arch. 5, 56.) The aqueous solution concentrated in a 
retort till it froths up and attains the consistence of oil, solidifies to a 
greenish-black crystalline mass, consisting of green crystals which pass to 
a higber state of oxidation even when kept in air-tight but not exhausted 
vessels. (Kemer, Ann. Pharm. 29, 183.) — The crystalline mass is greyish- 
black, radiating, and yields a bluish-green powder, which, when kept for 
4 months in a stoppered bottle, becomes covered with laminaB of iodine, 
and afterwards dissolves but partially in water, forming a black-brown 
solution, while ferric oxide remains undissolved. (Preuss, Ann. Pharm,, 

29, 329.) 

Anhydroui. Cry$taUized. Smith. 

Fe 27 .... 17-65 F« 27 .... 13-64 .... 14-14 

I 126 .... 82-35 I 126 .... 6364 .... 6364 

5HO 45 .... 22-72 .... 2222 

Fel 153 .... 100-00 +5Aq 198 .... 10000 .... 10000 

AqueotLs Protiodide of Iron, or Aqueous Hydriodaie of Ferrous Oxide, 
*— When 1 part of iron is brought in contact with 2 or 3 parts of iodine 
and with water, heat is evolved and a pale bluish-green solution formed. 
This liquid rapidly absorbs the oxygen of the air, with formation of ferric 
oxide— whereby a small quantity of basic salt is deposited — ^and evolution 
of iodine. This tendency to oxidation may be almost wholly prevented 
by adding sugar in quantity equal to twice that of the iodine, and 
evaporating to the consistence of syrup. (Frederking.) 

There appears to be no Sesqui-iodide of Iron, or TerhydriodaU of 
Ferric Oxide, 

1. When 2 parts of iodine diffused through water are saturated with 
iron, and 1 part more of iron added to the pale green filtrate (which is 
capable of taking up more than 1 pt.) there is produced a dark red-brown 
mixture, which smells strongly of iodine, and is probably a mere solution 
of iodine in aqueous protiodide of iron [hydriodite of ferrous oxide]; it 
exhibits the reactions of a ferrous salt: Oreen precipitate with caustic 
al]<alis and green with alkaline carbonates, soon turning red-brown; no 
colouring with sulphocyanide of potassium (but on the addition of sesqui- 
chloride of iron, the red colour immediately appears); blue with starch; 
and nevertheless a blue precipitate with ferrocyanide of potassium. The 
mixture when evaporated gives off iodine and leaves a brown-red mass. 
(Kemer, Ann. Pharm. 30, 117.) — The precipitate formed by ferrocyanide 
of potassium is light blue at first and afterwards [in consequence of the 
free iodine?] becomes dark blue. Ferricjranide of potassium gives imme- 
diately a dark blue precipitate. The solution evaporated to the consistence 
of syrup, whereby iodine is evolved, crystallizes on cooling in very 
deliquescent red-brown needles, from which water extracts protiodide of 
iron containing excess of iodine, and leaves ferric oxide. (Oberdbrffer, 



FERRIC lODATE. 249 

N. Br. Arch. 22, 296.)-— 2. Aqueous hydriodic acid prepared from 
126 parts of iodine, when gently heated with excess of recently preci- 
pitated hydrate of ferric oxide, dissolves a quantity corresponding to 
62*56 parts of the anhydrous oxide. The solution smells of iodine and 
exhibits the reactions mentioned under (1); hence it would appear that 
part of the ferric oxide and the hydriodic acid decompose each other, 
yielding protiodide of iron, free iodine, and water. (Kemer.) [The 
quantity of ferric oxide which Kemer found to be dissolved, is too great 
to correspond with the formula: Fe*0»+3HI=2FeI + I + 3Hq.]— -The 
yellowish-rod solution of ferric oxide in aqueous hydriodic acid is partly 
resolved, by heat into protiodide of iron and free iodide. (Lassaigne, 
J, Chim. mSd. 5, 833.) — 3. Aaueous protiodide of iron deposits ferric 
oxide when exposed to the air; tiie remaining liquid, however, contains no 
sesqui-iodide of iron, but (to judge by its reactions with alkalis) protiodide 
of iron and free iodine. (P. Squire, Phil, Mag. J. 9, 79.) 

According to Berzelius, the brown powder which is deposited on 
exposing aqueous protiodide of iron to the air, is not pure ferric oxide, but 
a basic salt. 

B. lodcUe of Ferrous Oande, or Ferrous lodcUe f'^lron dissolves 
without effervescence in iodic acid either dilute or concentrated; when the 
solution is boiled, a white powder is precipitated. (A. Connell, iT. Edinh. 
Phil. J*. 11, 72.) — lodate of potash gives a yellowish-white precipitate 
with solution of green vitriol. TPleischl.) The precipitate is soluble in 
excess of solution of green vitriol; hence, it is only on the addition of 
considerable quantities of iodate of potash, that the precipitate, which is 
of a dingy flesh-colour, becomes permanent. It has an astringent, ferru- 
ginous taste. It dissolves sparingly in water, readily in solution of green 
vitriol; the latter solution, when boiled, deposits basic iodate of ferric 
oxide, iodine being set free at the same time. (Geiger, Mag. Fharm. 29, 
253.) — The precipitate which iodate of potash yields with green vitriol is 
white at first, but soon turns yellow, giving off iodine and increasing in 
quantity, ana afterwards changes to brown basic iodate of ferric oxide. 
The mother-liquid, which has a yellow colour, deposits an additional 
quantity on boiling, and is afterwards found to contain free hydriodic 
acid. ^Rammelsberg, Fogg.. 44, 559.) — ^With hydrochlorate of ferrous 
oxide iodate of potash gives a white precipitate, which when heated gives 
off chlorine and turns brown. (Simon.) 

C. Iodate of Fbrrio Oxide. — a. Basic Salt. — Precipitated, on 
heating a mixture of iodate of potash and green vitriol, in the form of a 
yellowish-brown powder, having an astringent, ferruginous taste. When 
heated in contact with paper, it detonates and gives off iodine vapour. 
(Geiger.) — The light brown precipitate which forms when the mixture is 
left to stand in the cold for some time, dissolves in hydrochloric acid with 
rapid evolution of chlorine, whereupon ammonia throws down a mixture 
of hydrated ferric oxide and iodide of nitrogen, which detonates violently 
when dry. Dissolves readily in nitric acid, forming a liquid which 
contains no hydriodic acid, since it gives with nitrate of silver-oxide a 
copious precipitate perfectly soluble in ammonia. The light brown 
precipitate contains 19*28 per cent, of ferric oxide, 70*73 iodic acid, and 
9-99 water; it is therefore 3FeW,5lO*-hl5Aq. (Rammelsberg.) [The 
formula 4Fe'0^7IO^+18Aq. corresponds still more closely with the 
analysis; but both these fonuuk? are improbable.] 



250 IRON. 

5. BiniccUUe.'^liydic BCid and iodate of potash fonn with bjdrochlorate 
of ferric oxide a white precipitate soluble in excess of the ferric hvdro- 
chlorate. (Pleischl.) This precipitate, after washing and drying, has a 
dirty white colour and a weak ferruginous taste; is resolved by heat into 
iodine vapour and ferric oxide; deflagrates with a violet light when heated 
with charcoal powder; dissolves readily in hydrochlorate of ferric oxide 
and in 500 parts of cold water. The latter solution is colourless, but 
turns slightly brown when heated and deposits a few flakes. ^Geiger.^^ 
The precipitate obtained with iodate of soda and sulphate of lerric oxide 
and ammonia is yellowish-white, with a tinge of red after drying; is 
resolved at a red-heat into oxygen gas, iodine vapour and ferric oxide; 
and is sparingly soluble in nitric acid. (Rammelsberg.) 

lUttiin^berg. 

Pe«0» 78 .... 16-18 .... 15-92 

2IO» 332 .... 68-88 .... 69-37 

8H0 72 .... 14-94 .... 14-71 

W0«,2IO» + 8Aq. 482 .... lOO'OO Z 100-00 

D. and E. Ferrous and Ferric Periodates. — Mono-iodate of soda 
gives with ferrous and also with ferric salts, yellowish- white precipitates 
soluble in dilute nitric acid. (Benckiser, Ann. Fharm. 17^ 260.) 



Irok akd BnoMtKE. 

A. Protobromide of Iron, or Ferrous BROMtBB. — Bromine does 
not act upon iron in the cold. (Berthemot.) — 1. When bromine vapour 
iH passed over gentlv ignited iron wire, the wire glows vividly, fuses, and 
is converted into yellowish protobromide of iron. (Liebtg, Schw. 48, 107.) 
•—Iron filings similarly treated bake together into a greyish mass covered 
with golden-yellow scales of [sesquifj bromide of iron which may be 
sublimed. (Berthemot, Ann, Ckim. rhyi. 44, 391 ; also J. Fharm, 16, 657.) 
— 2. When iron filings are heated with hydrobromate of ammonia, 
hydrogen gas and ammonia are evolved, and bromide of iroll in a very 
difficultly fusible state remains behind. (L&wig.) — 3. A solution of iron 
in bromine and water, the iron being in excess, leaves dry bromide of 
iron when evaporated. (Berthemot.) — Protobromide of iron, when ignited 
in the air, yields a sublimate of sesquibromide of iron, while sesquioxide 
remains behind. (Lowig.) 

AqueouB Protobromide of Iron, or Hydrobromate of Ferrous Oxide, — 
When bromide of iron is dissolved in water, or when iron is dissolved in a 
mixture of bromine and water, or in aqueous hydrobromic acid, a pale 
green solution is obtained, which, when cooled after evaporation, yields 
rhombic tables of sex-hydrated bromide of iron, and when exposed to the 
air turns brown and deposits ferric oxybromide. (Ldwig.) 

AAhydnmt. Bertfaemot. 

Fe « 27-0 .... 25-62 .... 26-04 F« «.. 27*0 .... 16-94 

Br 78-4 .... 74-38 ..,. 73-96 Br 78-4 .... 49-18 

OHO 540 .... 33-88 



FcBr 105*4 .... 100-00 .... 10000 +6Aq 159*4 .... 10000 

B. SEsauiBROMiDB OF Iron, or Ferric Bromide.-*-] . By heating the 
protobromide with bromine. (ii5wig.)-*2. By evaporating to dryness a 



IRON AND CHLORINB. SSt 

solution of iron in excess of bromine-water. (Liebig. — Brown-red; fuses 
at a gentle heat; while, at a higher temperature, part of it sublimes in 
laminaa resembling mosaic gold, and the rest is resolved into vapour of 
bromine and a residue of ferrous bromide. (Ldwig.) 

Aqtteous Sesqutbromide of Iron, or HpdrobromcUe of Ferric Oxid€.-^- 
Sesquibromide of iron deliquesces when exposed to the air. (Liebig.)-— 
The same solution is obtained by dissolving hjdrated ferric oxide in 
aqueous hydrobromio acid, or by mixing aqueous protobromide of iron 
with bromine. The solution, which is of a yellowish-brown colour, much 
darker than that of the sesquichloride, and has a strongly ferruginous 
taste, gives off hydrobromic acid when evaporated, and deposits the fol- 
lowing compound. It does not yield crystals when concentrated to the 
consistence of a symp ; but when completely evaporated, leaves a brown- 
red mixture of the following compound and sesquibromide of iron, which 
latter may be sublimed by heat. (L5wig.) 

C. Ferric Ozybromibe. — ^A compound of sesquioxide of iron with 
the sesquibromide. — Precipitated on evaporating the aqVieous solution of 
sesquibromide of iron, or on mixing it with an insumcient quantity of 
potash-ley, or on exposing aqueous protobromide of iron to the air. 
(Lowig.) 

Bromine-water converts hydrated ferrous oxide into hydrated ferric 
oxide and bromide of iron, which dissolves; not a trace of ferric oxide is 
taken up. (Balard.) 

^romate of Ferrous Oxide does not appear to exist. Green vitriol 
yields with bromate of potash a brown-red precipitate, which dissolves in 
a larger quantity of water, forming a brown-red solution. (Lowig.) This 
precipitate consists of basic sulphate of ferric oxide, and the liquid con- 
tains free bromine. (Rammelsberg.) Bromate of potash yields, with 
hydrochlorate of ferrous oxide, without precipitation, a darker mixture, 
which acquires a dark brown colour when heated. (Simon.) 

D. Brohatb op Ferric Oxide, or Ferric Bromate. — Recently 
precipitated hydrate of ferric oxide yields, with aqueous bromic acid, a 
reddish-yellow solution, which, when evaporated over oil of vitriol in a 
receiver filled with air, acquires a greenish tinge, and without yielding 
crystals, forms a syrup, and afterwards, on evaportltion over the water- 
bath, a dark brown mass, from which water dissolves out the smaller 
portion, forming a yellowish solution, while the greater part remains 
undissolved in the form of a quirUohasic mU. This, when ignited, evolves 
water, oxygen gas, and bromine vapour, and leaves black ferric oxide; it 
dissolves in nitric acid. (Rammelsberg, Fo^^, 55, 68.) 

Rammelsberg. 

5Fe«0» 3900 .... 50-10 ........ 5089 

BrO» 118-4 .... 15-21 

30HO 2700 .... 84-69 83-73 



5FeW,BrO' + 30Aq. 778-4 .... 10000 



Iron anp Chlorinb. 



PROTocntOBiDB OF Iron, or FERitouB Chloride. — 1. Formed by 
boiling down a solution of iron in hydrochloric acid out of contact of air, 
and heating the residue till the water is expelled. The teniting may be 



252 IRON. 

performed in a glasa tube dosed at one end, and drawn out to a fine point 
at the other; or in a stream of hydrogen gas. — Q. By passing chlorine 
gas through a red-hot gnn-barrcl filled with iron turnings, the barrel 
being connected immediately at the part which projects from the furnace, 
with a receiver in which the chloride of iron sublimes. — 3. By passing 
hydrochloric acid gas over red-hot iron filings. — 4. When iron filings are 
heated with sal-ammoniac, protochloride of iron remains in the residue. 

When prepared by method (1), it is white (Chevreul), without metallic 
lustre, opaque, and has a laminar fracture; fuses at a red heat, but does 
not volatilize even at the melting point of glass. (J. Davy, Sdiw. 10, 326.) 
— By (2), small white scales are obtained. (Thenajrd, Traits.) — By 
^3), white micaceous scales. (Wohler & Liebig, Fog^. 21, 582.) — By 
(4), Pagenstecher (iV^. Tr, 3, 1, 399) obtained a mass consisting of soft, 
white, silky laminae, which dissolved in water without evolution of heat, 
and formed a colourless liquid, which turned green in the air, and gave 

a black precipitate with ammonia. 

J. Davy. 

Fe 27-0 .... 43-27 46-57 

CI 354 .... 56-73 53*43 

FeCl 62-4 .... 10000 10000 

Decomposed by ignition in a stream of oxygen gas or with chlorate 
of 'potash, yielding ferric oxide and chlorine. (Gay-Lussac.) When 
heated with moderate excess of air, it gives up one-third of its iron to tho 
oxygen, and is converted into sesquichloride of iron which sublimes, and 
sesquioxide which remains behind : 

6FeCl + 30 =: 2Vt?Cl^ + Fc^O*. 

When brought in contact with vapour of water at a red heat, it gives off 
hydrochloric acid and hydrogen gas, and is converted into ferroso -ferric 
oxide. (Gay-Lussac, Ann. Chim. Fhys. 22, 424.) 

3FeCl + 4H0 = Fc»0< + 3HC1 + H. 

With phosphuretted hydrogen gas, even at ordinary temperatures, it 
forms hydrochloric acid gas and phosphide of iron. (H. Rose, Fogg, 
24, 301.; — Oil of vitriol decomposes it, even when cold, the products being 
hydrochloric acid gas and ferrous sulphate. (A. Vogel.) Does not yield 
sulphide of iron when ignited with sulphur. (A. Vogel.) 

TetrorhydrcUed Frotockloride of Iron, or Ter-hydraied Hydrochloraie 
of FerroiLS Oxide, — Formed by evaporating and cooling a saturated solu- 
tion of iron in hydrochloric acid out of contact of air. — Hydrochloric acid 
is boiled with excess of iron in a narrow-necked flask, till it is thoroughly- 
saturated and sufficiently concentrated; the liquid thereby acquires a 
brownish-grey colour, and often, towards the end of the operation, becomes 
pale grey from formation of a basic ferrous salt, and exhibits a tendency 
to frothing; hence the heat must be kept moderate towards the close of 
the process. The solution is then— as in the preparation of green vitriol — 
passed through a filter moistened with water, the filter being placed in a 
funnel having a long neck which reaches to the bottom of a vessel pre- 
viously rinsed out witli hydrochloric acid. The resulting crystals are 
exposed to sunshine at a temperature between 30^ and 40^, and constantly 
turned till they are dry; they are then preserved in stoppered bottles. 
They keep best when they have been dried at 50°: at that temperature, 
however, they effloresce slightly, (v. BousdorflT, Fogg. 31, 89.) — Light 



FERRIC CHLORIDE. 253 

blue, tronslacent, oblique rbombio prisms, truncated on tbe acute lateral 
edges (Fig, 87), without the t- and A-faces; often shortened into tables. 
(Bonsdorff.) Pale green, broadly truncated rhombic octohedrona, or 
rhombic prisms acuminated with octohedral faces. {Figs* 42 and 44 j 
Reimann, Mag, Pharm. 17, 215.) — In ordinary air, tbe crystals soon 
acquire a grass-green colour; in air dried by oil of yitriol, they quickly 
effloresce to a white powder. (Bonsdorff.) When heated, they fuse in 
their water of crystallization. (Reimann.) 

When iron is dissolved in strong hydrochloric acid, crystals are formed 
at a certain stage of the operation, which dissolve in water with decrepi- 
tation and evolution of an inflammable gas. (Hess, J. pr, Ghem. 25, 126): 

CrystalliMed, BonBdorff. Rdmann. 

Fe 27-0 .... 27-44) .-.g. i 

CI 35-4 .... 33-98/ ^^ ^^ •"' 133-33 

4H0 360 .... 36-58 36-05 

FcCl + 4Aq 98m[ .... 100-00 ZZ 10000 

According to Graham, also {Ann. Pharm, 29, 31) the crystals contain 
4 At. water to 1 At. chloride of iron. 

Protochloride of iron, whether dry or hydrated, deliquesces rapidly in 
the air and dissolves readily in water and alcohol; 1 part of the hydrated 
salt requires 0*68 cold water to dissolve it. (Reimann.) 

The aqueous solution of protochloride of iron — ^in the same manner as 
ffreen yitriol — absorbs i At. nitric oxide gas, and thereby acquires a 
dark greenish-brown colour. 249*6 pts. (4 At.) protochloride of iron 
dissolved in either a large or a small quantity of water, absorbs 25*14 
pts. of nitric oxide, and the mixture exhibits the same relations as that 
obtained with green yitriol. — Dry protochloride of iron likewise absorbs 
a small quantity of nitric oxide, and becomes dark-coloured. 100 parts 
of dry protochloride of iron absorb from 2 to 3*66 parts of perfectly dry 
nitric oxide gas. (Graham.) — ^A much larger quantity is absorbed by the 
solution of dry protochloride of iron in absolute alcohol, which thereupon 
becomes nearly black. A solution of 1 pt. chloride of iron in 5 pts. 
alcohol saturated with nitric oxide, evolves a portion of that gas wnen 
heated, boils at 100^, giving off the remainder of the nitric oxide in its 
original state, the volume of the gas evolved being 23 times that of the 
alcohol; after several hours* boiling, the liquid regains the colour which 
it had before saturation with the gas. (Graham, Phil. Mag. Ann. 4, 265 
& 331; also Schw. 55, 200.) 

B. SESQuicnLORiDE OP Iron, or Ferric Chloride. — PercMoride of 
Iron; Iron Svblimate. — 1. A piece of iron wire or a watch-spring intro- 
duced red-hot, or with a piece of burning tinder at the end, into chlorine 
gas, bums with a red glow and forms this compound, which then sublimes. 
The same result may be obtained by passing chlorine gas over gently 
heated iron. — 2. Protochloride of iron heated in chlorine gas, is converted 
into the sesquichloride. — 3. When protochloride of iron is heated in a 
vessel containing air, sesquichloride sublimes, and sesqnioxide remains 
behind. — 4. When an aqueous solution of the sesquichloride is evaporated, 
the dry compound remams behind, mixed with more or less ferric oxy- 
chloride ; the dry residue gently ignited in a loosely closed flask, yields 
the sesquichloride sublimed in laminie. — 5. A mixture of 1 pt. calcined 
ferrous Bulphate, and 1 pi. chloride of calcium, is ignited in a flask till the 



254 litOK. 

feme cbloride ^uUimea. (Ba«r, £^p^, 85, 432.)^Iron-bladr, irideaoenl 

tables, having a m^tallio lustre, mi volatilUing and eabliming somewhat 

above 100^ 

J. Davy. 

2Fe 540 .... 33-71 351 

3Cl „. 1062 .... 66-29 649 

Fe^.W ,. 160-2 .... 10000 ZZ] IQO'O 

When Heated in contact with oxygen gas, it yields ferric oxide and 
chlorine ; boated with aqaeons vapour, it tonus ferric oxide and hydro- 
chloric acid gas. With oil of vitriol and with sulphur^ it behaves like 
the protochloride. (A. Vogel.) 

Hydrated SesquiMoride of Iron, or ffydroeklorate of Ferric Oxide, — 
Sesquichloride of iron dissolves in water with considerable evolution of 
hea^ and likewises deliquesces in the air. The liquid formed by deli- 
quescence is called Oleum Martin, The same solution maybe obtained by 
the folio wiug methods : 1. By dissolying ferric oxide or its hydrate in 
boiling hydrochloric acid. Pure blood-stone finely pounded may likewise 
be nsed for this purpose. (Mohr.) 2. By dissolving iron to saturation in 
a definite quantity of hydrochloric acid; filtering the solution, and mixing 
it with half as much hydrochloric acid as it already contains; then heating 
the liquid to ebullition in a capacious vessel, and adding nitric acid in 
small portions till the dark brown colour first produced by the absorption 
of nitrous gas has given place to a yellowish-brown, and the further addi- 
tion of nitric acid produces no evolution of nitrous gas. The mixture is 
very apt to froth over, especially towards the end of the operation, when 
all the nitric oxide which has been absorbed is evolved. The same result 
may also be obtained by dissolving iron in aqua-regia; but it is not easy to 
hit the right proportion of the acids. — 3. By passing washed chlorine gas 
through aqueous hydrochloric acid saturated with iron, as long as the gas 
is absorbed. The dark brown liquid, which has a rough taste and colours 
the skin yellow, yields, on evaporation and cooling, crystals containing 
two different proportions of water. 

a. PerUa-hydrated. — 1. Obtained by evaporatiiu; the liquid to a syrnp 
-^mixing it with a small quantity of strong hydrochloric acid to re-dissolve 
the precipitated ferric oxychloride — ^and leaving it to itself in the cold. 
(Stein, Repert. 13, 264.)-:-2. By fusing the crystals 6— evaporating till 
the liquid becomes perfectly solid on cooling — replacing the lost hydro- 
chloric acid — ^and leaving the solution to cool. (Fritxsche.) — 3. The 
crystals &, placed beside oil of vitriol under a receiver containing air, 
soon deliquesce and form a thick liquid, in which large crystals then form, 
till the whole is converted into a mass of crystals. (Fritzsche, J, pr. Ckem. 
18, 479.) Aurora-red tables (Stein); large, deep, reddish-yellow crystals, 
which fuse readily, and solidity ap,in at 42"^; they absorb water from the 
air very rapidly, and with evolution of heat. (Fntzsche.) 











Fritzscke {mean,) 


2Fe 


54-0 


•«•• 


26-32 


27-42 


3C1 


106-2 


«••• 


51-75 


5072 


6H0 


450 


.... 


21-93 


21-86 



Fe*Cl» + 5Aq 205*2 .... 100*00 100-jO 

When the crystals a and 5 are shaken together, a slight hX\ of tempera- 
ture takes place, and a liquid is obtained— the same as tliat produced by 



FERRIC OXTCfiLORIDB. 256 

imperfect evaporation of tbe oyttals h — ^whioli prodaoe9:great heat when 
mixed with water. (Fritxsche.) 1 At. ferric chloride dissolved in 9 At. 
water yields a liquid, which ia identical with the Oleum Martis of the 
older chomiete (as obtained bj deliquescence of the solid chloride in the 
air), has a density of 1*545, and refuses to cTystallize. (Kinast.) Hence 
there are two solntions of ferric chloride in water to be distinguished; one 
containing more than 5 and less than 1 2 atoms of water, the other con- 
taining more than 12 atoms. 

h, Dodeea-hydraUd, — Ferric chloride deliqneeoes rapidly in the Air, 
then crystallizes in the form of this salt» and afterwards deliquesces much 
less quickly. (Kinast, Kastn, Arch. 20, 281.) This salt likewise separates 
slowly from an aqueous solution of the chloride not too much concentrated 
— ^6ne radii stretching out in all directions from particular points, and 
forming pale orange-yellow, opaque, hemispheric nodules, into which the 
whole liauid is ultimately converted. If the evaporation has been carried 
too far, tne syrup will not crystallize unless it be exposed for some time 
to the damp air of a cellar, from which it can absorb water. (Mohr, Ann, 
Pharm, 29, 173.) A crystalline mass of this nature, having been kept 
for half a year in a stoppered bottle, was found to be converted into 
brown-red transparent rhombic tables [of salt a 1], surrounded by a small 
quantity of liquid. (Winckler, Repert. 67, 150.) 



2Fe 54-0 

3Cl 106-2 

12HO 1080 





Fritf sehe {mtan^ 


Mohr. 


20-13 


21-57 .... 


20-59 


39*60 


3907 .... 


39-23 


40-27 


39-36 .... 


40-18 



FeSCIs+12Aq 2682 .... lOO'OO 100-00 .... 10000 

AqueouM Sesquichloride of Iron, or Aqueotis Terhydrochlcrcde of Ferric 
Oxid^. The salt b deliquesces slowly in the air. The aqueous solution, 
when evaporated, gives off more or less hydrochloric acid, depositing 
ferric oxychloride; and if evaporated to perfect dryness— whereupon a 
further quantity of acid, together with some ferric chloride, is given off— « 
it leaves a mixture of ferric chloride with ferric oxychloride. When 
silver is immersed in the solution, protochloride of iron is formed, and 
the silver is converted into chloride, which is black at first, but after- 
wards turns white. (Wetzlar.) 

Ferric chloride is likewise soluble in alcohol and in ether; but if 
exposed to light or heat, it is converted, especially by the ether, into 
protochloride. The solution of ferric chloride in a small quantity of 
alcohol of 96 per cent., remains liquid at 7'5®; but, if stirred with a glass 
rod, immediately solidifies to a solid yellow crjrstalline mass, whereupon 
the temperature rises to -hi 9^ (Winckler.) 

C. Ferric OxYOHXfORiDB, or Basio Hydrochlorate op Ferric 
OxiDB.-^€i. Soluble Compound. — When recently precipitated hydrate of 
ferric oxide is added to an aqueous solntion of ferric chloride, as long 
as it dissolves, a dark red liquid is obtained, having a specific gravity of 
1 '017. This liquid does not become turbid on boiling, dilution, or evapo- 
ration to dryness; but if mixed with a few drops of nitric acid, it deposits 
the greater part of the oxide in the form of a basic compound^ and gives 
a dark bluisn-green precipitate with ferrocyanide of potassium. A sample 
of this liquid yielded by precipitation with potash, 155 parts of ferric 
oxide, and afterwards by precipitation with nitrate of silver (after addition 



! 



256 IRON. 

of nitrio acid) 80 parts of chloride of silver. [Henee this oompoand 
appears to coasist of 14Pe'0' + Fe*Cl'.] If more hydrated oxide be added 
to the liquid than it is able to take up, the soluble compound unites with 
it, and forms the insoluble variety. (Phillips, PhU. Mag, Ann, S, 406; 
iJso Br. Arch. 39, 39.) 

h. Insoluble Compound. — Precipitated in rust-brown flakes when 
hydrochlorate of ferric oxide is mixed with an insufficient Quantity of an 
alkali, or when it is evaporated, or when the mono-hydrochlorate of 
ferrous oxide is exposed to air in the hydrated state. When heated it 
first gives off water, then ferric chloride, and leaves ferric oxide. 

HypoMoriU of Ferric Oxide does not appear to exist. Hydrated 
ferric oxide dried in the air, and then introduced into dry chlorine gas, 
quickly fuses into a dark red liquid, which decolorizes indigo and givea 
off all its chlorine at a boiling heat, leaving ferric oxide. (Gronvelle.) 
The absorption goes on slowly; the solution exerts a decolorizing action, 
evolves chlorine and hypochlorous acid when heated, and deposits the 
ferric oxide. It appears to consist of sesquichloride of iron and free 
hypochlorous acid, which, on the application of heat, are resolved into 
free chlorine and ferric oxide. Aqueous hypochlorous acid does not dis- 
solve ferric oxide; and when hypochlorite of lime is mixed with ferric 
sulphate, the ferric oxide is precipitated together with the sulphate of 
lime, and free hypochlorous acid remains in the liquid. (Balard.) 

D. Pkrchloratb of Ferro0s Oxide, or Ferrous Pbrchloratb.— 
When green vitriol is precipitated by perchlorate of baryta, and the 
liquid filtered and evaporated, long colourless needles are obtained, which 
remain permanent for a long time in the air, and then oxidize in the 
manner of green vitriol. They scarcely detonate on glowing coals. When 
the solution is evaporated in the air, a small quantity of ferric salt is 
formed, (SeruUas^ Ann* Chim. Phy$. 46, 305.) 



Iron and Fluorine. 

A. Protopluoride op Iron, FeF, and Monohydrofluatb of 
Ferrous Oxide. — Iron dissolves in warm aqueous hydrofluoric acid, with 
evolution of hydrogen. The liquid, when evaporated, yields white rect- 
angular tables, which turn pale yellow in the air. These crjrstals, when 
gently heated, give off water, and are converted into the dry protoflnoride 
of iron, which undergoes no alteration when ignited in the air; but if the 
ciTstals are suddenly heated, a small quantity of hydrofluoric acid goes 
off together with the water, and the residue has a red tinge from admix* 
ture of ferric oxide. The crjrstals dissolve with difficulty in pure water 
—more easily in water containing hydrofluoric acid. Alkalis precipitate 
hydrated ferrous oxide from the solution. Protofluoride of iron combines 
with the fluorides of the alkali-metals, forming colourless, difficultly fasible 
compounds. (Berzelius.) 

B. Sesquifluoride op Iron, Fe'F', and Ter-hydrofluate of 
Ferric Oxide. — Formed by saturating aqueous hydrofluoric acid with 
hydrated ferric oxide. The colourless solution, when evaporated, deposits 
pale flesh-coloured crystals, having a sweet and rough taate. These 
crystals ro-dissolvo perfectly, but slowly, in water, forming a colourless 



PERROUS NITRATE. 257 

liquid. Sesqui fluoride of iron combines with other metallic fluorides^ 
forming compounds which, for the most part, are nearly or quite insoluble, 
but nevertheless are not deposited from a mixture of tne aqueous solutions 
of the two fluorides till heat is applied. (Berzelios.) 

C. Ferric Oxyfluoridb, or Basic Hydrofluate of Ferric Oxide. 
Precipitated on mixing the aqueous solution of B with excess of ammonia. 
Rusty-jellow powder. (Berzelius.) 



Iron and Nitrooek. 

A. Nitride of Iron.— Dry ammoniacal gas passed over iron wire 
heated to redness in a tube, is resolved into hydrogen and nitrogen gases, 
and the iron becomes very brittle, though it does not perceptibly increase 
in weight. (A. BerthoUet, Gilh. 30, 378.) The increase in weight, after 
the gas has been passed over the iron for 24 hours, does not exceed 0'2 
pts. for 100 parts of the iron. (Thenard, Ann, Cfiim, 85, 61; also GUh. 
40, 207.) After 9 hours' passage of the gas, it amounts to only 0*15 to 
every 100 parts of iron; after 2 honrs' passage of the gas, the iron 
appears brittle, exhibits the fine-grained fracture of steel, may be hardened 
in the same manner as steel, and will then give sparks with flint; but 
after 9 hoars' passage of the gas, it is even softer than common iron, no 
longer admits of hardening, and its specific gravity is diminished from 
7-788 to 7-6637. (Savart, Ann. Chim.Fhys. 37, 326; also Po^g. 13, 172.) 
—When ammoniacal gas, freed from water and carbonic acid by passing 
over chloride of calcium and hydrate of potash, is passed for 6 or 8 hours 
over red-hot iron, 100 parts of the iron increase in weight by 7 to 11*5 
pts. [11 '5 : 100=14 : 121*7; hence each atom of nitrogen is united with 
more than 4 At. (108 pts.) and less than 5 At. (135 pts.) of iron]. The 
nitride of iron thus obtained is white, brittle, and even friable; its spe* 
cific gravity often does not exceed 5*0; with the magnet and with acids 
it acts like other iron, but is more readily altered by air and water. — 
Hydrogen gas, passed over red-hot nitride of iron, withdraws the nitros^en 
from it and forms ammonia; a case of reciprocal affinity. The hydrogen 
gas evolved when nitride of iron is dissolved in dilute sulphuric acid 
contains abont 6 per cent, of nitrogen; the quantity of gas evolved is 
also less than when pure iron is used, because sulphate of ammonia is 
formed at the same time. Sometimes the iron, after ignition in ammo- 
niacal gas, is found to be altered in its physical properties, as above 
described, and yet has not increased in weight; m such a case, the 
combination of the nitrogen with the iron is but transient, but has the 
efi'ect of altering the mutual arrangement of the atoms. (Despretz, Ann, 
Chim. Fhys. 42, 122; also Fogg. 17, 296.) 

B. Nitrate of Ferrous Oxide, or Ferrous Nitrate.— Profoni^rate 
of Iron. — 1. Formed by precipitating nitrate of baryta with an equivalent 
quantity of ferrous sulphate and evaporating the filtrate in vacuo over 
oil of vitriol. — 2. By dissolving iron in very dilute nitric acid, and expos- 
ing the solution to the air to free it from nitric oxide, which gives it a 
greenish-brown colour. (H. Davy.) — The iron should be immersed in 
water, and nitric acid free from nitrons acid and chlorine, added in small 
portions and with constant agitation, so that the temperature may not 
rise above 50°; as often as the liquid cools down, fresh acid must be 

VOL. v. 8 



258^. IRON. 

added. Under these oironiiiBtances, no gas is eyolyed^ 1>Qt liitrate of 
ammonia is fanned at the same time. (Berzelius.) 

8Pe + 10NO» + 3HO = 8(FeO,NO») + NH»,NO*. 

1 part of nitric acid with 3 parts water evolves no gas in acting npon 
iron; with 2 parts water, nitrous oxide is at first evolved, mixed with 
nitric oxide; afterwards only the latter. (Pleischl, Schw. 38, 464.) — 
The pale green solution thus ohtained does not deposit ferric oxide or 
give ofi" nitric oxide gas, till it is heated to the hoiling point. (Berzelins, 
Pogg, 27, 121.) — 3. Protosulphide of iron dissolves in dilute nitric acid 
surrounded with a frigorific mixture, hjdrosulphnric acid being evolved 
and a greenish liquid fomfed, which, on the slightest rise of temperature, 
is converted into a ferric salt. (Berzelius.) — 4. The solution of scale-oxide 
of iron in strong nitric acid yields, after a while, nearly colourless, right- 
angled four-sided prisms with dihedral summits. These crystals deliquesce 
in the air, and have a sharp taste. Schonbein regards them as con- 
sisting of ferric nitrate, to be immediately describea. The solution of 
the scale-oxide, when heated or exposed to the air, is converted into ferric 
nitrate, with deposition of yellow flakes. (Vauquelin.) 

C. Nitrate of Ferric Oxide, or Fbrric Nitrate. — PemitrcUe of 
Iron, — Nitric acid, when not too dilute, attacks iron very energetically, 
great heat being produced, nitric and nitrous oxide evolved, and nitrate 
of ammonia formed at the same time; if the acid is in excess, a brown 
solution is formed; if it is deficient, a yellowish-brown basic salt is the 
result. 

a. Acid SdU,—-u, Formed by dissolving iron, ferric oxide^ or its- 
hydrate in heated nitric acid. The anhydrous oxide dissolvea very 
slowly in nitric acid, much less readily than in hydrochloric acid. — The 
yellowish'brown solution becomes syrupy on evaporation, and subse- 
quently leaves a brown residue which gives off its acid when gently 
heated, so that first a basic salt and afterwards pure ferric oxide is left. 

/9. When 1 volume of the concentrated solution m is mixed with 
5 volumes of water, and the yellow mixture gradually heated till it boils, 
it assumes a deep blood-red colour — retains this colour without becoming 
turbid, on cooling, — and then, on the addition of a small quantity of nitric 
acid, deposits the basic salt 6, 0, from which the colourless liquid must be 
quickly filtered, before the precipitate re-dissolves. The colourless 
liquid, evaporated to a syrup and then left to itself in close vessels^ 
crystallizes in colourless or pale yellow cubes. The brown solution a^a 
may also be mixed with an additional quantity of nitric acid: it thereby 
becomes nearly colourless, and on the subsequent addition of water, loses 
all its colour, and then, after filtering and evaporation, yields the same 
cubes. The yellowish colour of the cubes disappears almost wholly 
when they are dried between bibulous paper, the mother-liquid being 
thereby absorbed. [Frey (Kastn, Arch, 14, 176), by a method which he 
does not describe, obtained rhombohedrons with truncated edges; angles 
of the rhombohedron = 78*^ and 102°.] — The crystals fuse at a tempera* 
ture below 50^; they deliquesce rapidly in the air, forming a liquid of a 
honey-yellow colour, and dissolve m all proportions in water. A some* 
what concentrated solution turns yellow on each application of heat, the 
colour being stronger the higher the temperature; a very dilute solution 
becomes permanently yellow by boiling, and if nitric acid be added to it, 
after cooling, it again deposits a certain quantity of the basic salt b,p, 
(Schonbein, Pogg, 39, 1 4 1 .) 



L.: 



FERRIC AZOPHOSPHATE. 269 

5. Basic 8dU,-^». Precipitated when a perfectly satarated solution of 
ferric oxide in nitric acid ia diluted or boiled; or when a,at is mixed with 
a quantity of alkali not sufficient to precipate it completely. It is also 
formed by digesting hydrated ferric oxide with the acid solution of UyU, 
or with a quantity of nitric acid not sufficient to dissolve it; by boiling a 
very dilute solution of a^a containing the smallest possible excess of acid; 
aud by evaporating the solution of a,a to dryness^ and carefully heating 
the residue. — Brown, gelatinous when moist, and partly soluble in per- 
fectly pure water, forming a red solution. (Berzelius.) The product 
obtamed by heating a,a contains, according to Grouvelle, 81*26 (4 At.) 
ferric oxide, 14'06 (1 At.) acid, and 4*68 (2 At.) water. 

p. For the preparation, see a,/3. Ochre-yellow powder, easily soluble 
in pure water, in which it forms a deep blood-red solution. The solu- 
tion, when concentrated by evaporation, solidifies in the cold to a black- 
brown jelly. Nitric acid added to the aqueous solution precipitates 
a portion of the salt. The dry salt dissolves slowly in cold, and quickly 
in warm nitric acid, forming a colourless liquid which exhibits the same 
characters as the solution of a,0. (Schonbein.) 

When a ferrous salt is supersaturated with ammonia and the liquid 
filtered, a colourless solution is obtained which quickly turns green in 
the air, and afterwards exhibits a brown turbidity, arising from the for- 
mation, first of hydrated ferrous oxide, and afterwards of hydrated ferric 
oxide. Hence an opinion has been entertained that hydrated ferrous 
oxide is soluble in ammonia. But the same liquid is formed when tho 
ammonia is not added in excess. — In fact, the filtrate contains a double 
salt, in which part of the acid of the iron-salt is combined with ferrous 
oxide, the rest with ammonia ; and the ammonia added in excess cannot 
precipitate the ferrous oxide which remains in solution, until the latter is 
converted into ferric oxide by exposure to the air. — Grotthuss {Sckw, 
80, 70) likewise found that iron is not soluble in aqueous ammonia, and 
that it neither precipitates copper from a solution of cupric oxide in 
ammonia, nor dissolves in that solution. 

IT. C'. AzopHospHATB OF Ferric Oxide, or Ferric Azophosphate. 
— ^When chlorophosphide of nitrogen (II. 474) is dissolved in alcohol^ 
and potash or ammonia added, decomposition instantly ensues; and if the 
liquid be then evaporated to dryness, the residue re -dissolved in water, 
and the solution neutralized and boiled with a ferric salt, a white floccu- 
lent precipitate speedily forms, having the appearance of ordinary ferric 
phosphate, but distinguished from that salt by being insoluble in dilute 
acids, and easily soluble in ammonia. — This salt is the azophosphate of 
ferric oxide. — It is immediately decomposed by solution of potash, 
azophosphate of potash being formed, and ferric oxide remaining undis- 
solved. Alkaline carbonates decompose it on the application of heat. 
When fused with potash, it evolves ammonia, and the fused mass re-dis- 
solved in acid and treated with ammonia, yields ordinary ferric phos" 
phate. Strong sulphuric acid dissolves it and decomposes it when 
warmed. — The salt when dried at ordinary temperatures, or at 100°, has 
a light buJ0F colour; but when heated to about 330^, it suddenly gives off 
vapour of water and ammonia, and assumes a dark brown colour, while a 
small quantity of a white crystalline body sublimes. The sublimate is 
soluble in water : the solution treated with nitrate of silver yields a 
white precipitate which immediately changes to a clear orange-red; and 
shortly afterwards there is formed a quantity of a black substance inso* 

s2 



260 IRON. 

lable in ammonia, apparently redaced silver.-— Tlio composition of ferric 
azophosphate is as follows : — 

Dried at or above 100^. GladBtone. 



Fc"0» 80 .... 34-19 .... 34-48 .... 33-90 .... 34-47 .... 33-62 

2P 64 .... 27-35 .... 2505 .... 25*07 .... .... 27*93 

N 14 .... 5*98 .... 5-67 .... .... 5*24 

4n 4 .... 1*71 .... .... .... 1*94 ...« l*ol 

90 72 .... 30-77 

234 .... 100-00 ' 

Or: 

Pe«0» 80 34*19 

P»NO» 118 50-44 

4HO 36 15-37 

Pe»0»,P»N0« + 4Aq. 234 ZZ 10000 

Dried at 76". Gladstone. Or : 

Fe»0».... 80 .... 32-92 .... 32*33 .... 32-87 Fe«0» 80 .... 3292 

2P 64 .... 26-34 .... 2392 P«NO» 118 .... 48*56 

N 14 .... 5-76 .... .... 500 5H0 45 .... 1852 

5H .... 5 .... 2-06 .... .... 2-36 

10 O .... 80 .... 32-92 ^^ 

243 ...100-00 Fc20»,P2NO» + 5Aq. 243 .... 100*00 

It is not easy to determine in what state tlie 5 atoms of water exist in 
the salt, inasmuch as no appearance of crystallization can be perceived, 
even with the aid of poweifal microscopes; but it is evident that one of 
the atoms must be differently combined to the rest, since it is driven 
off at 100°, while the others remain. (Gladstone, Chem, Soc. Qu, J. 
3, 142.) H 

D. Ferrite of Ammonia ? — ^Ferric oxide or its hydrate, whether 
natural or artificial, is always found, after exposure to the air for some 
time, to contain ammonia. 

E. Carbonate op Ferric Oxide and Ammonia. — Ferrico-ammanic 
CarhoncUe, — When a ferric salt is supersaturated with concentrated 
carbonate of ammonia, the precipitated ferric hydrate gradually re-dissolves 
in the liquid. The deep brown-red liauid, if diluted with water, again 
deposits the hydrated oxide after a while. — Hydrated ferric oxide pre- 
cipitated by ammonia from a solution of the sesquichloride, and well 
boiled with potash, is insoluble in carbonate of ammonia, according to 
Grotthuss; hence the presence of the ammoniacal salt produced in the 
precipitation, contributes to the re-solution of the hydrate. 

F. Phosphate op Ferrous Oxide and Ammonia. — Ferro9<Hzmmonic 
Phosphate, — Formed by mixing a solution of 14 parts of iron in hot 
hydrochloric acid with a small portion of sulphite of ammonia; adding 
to it while hot a thoroughly boiled aqueous solution of 100 pts. crystal- 
lized ordinary diphosphate of soda, which immediately precipitates white 
phosphate of ferrous oxide; then adding ammonia in slight excess — 
immediately closing the flask, which must be completely filled with the 
liquid — agitating — and leaving the mixture to itself for a few uynutes till 
the precipitate, which is flocculent at first, is converted into lamin88, 
which sink rapidly to the bottom. If it remains flocculent^ the liquid 



SULPHATE OF FERROUS OXIDE AND AMMONIA. 261 

mnfit be heated again, perhaps with the addition of a small quaDtity of 
ammonia; if part only of the precipitate becomes crystalline, tiie lighter 
flakes must be separated by levigation from the crystalline lamina). 
The lamiufB, on which the air no longer exerts any oxidizing action, are 
then thrown upon a filter, washed with thoroughly boiled water, and 
dried. No ammonia must be added to the water, because it imme- 
diately induces oxidation, so tbat hydrated ferric oxide remains on the 
filter, and the water runs off brown; hence also, in preparing the salt, 
care must be taken not to add too much ammonia. — Greenish-white, soft 
laminsB, which, when rubbed on the hand, produce a coating like silver; 
they are permanent in the air; the salt when heated in the air gives off 
water and ammonia, and leaves, first, greenish ferrous phosphate, amount- 
ing to 77 per cent. — then yellowish- white ferric phosphate. With potash- 
solution it evolves ammonia^ and when boiled therewith, gives up its 
phosphoric acid, and is converted into ferroso-ferric oxide having the 
form of the original laminsB. Insoluble in water, even at the boiling 
heat. While yet moist it dissolves readily in acids, even when dilute; 
but after drying, it dissolves but sparingly and with difficulty, even iu 
concentrated acids. (Otto, J. pr. Chsm. 2, 40D.) 

Otto. 

NH» 17-0 .... 917 8-77 

2FcO 700 .... 37-761 .^.^rt 

cPO» 71-4 .... 38-51/ ^'"" 

3H0 27-0 .... 14-56 

NH*0, 2FeO, cPO* + 2Aq 185-4 .... 100-00 

This composition is analogous to that of phosphate of magnesia and 
ammonia dried at 1 00°. (Graham.) 

The greenish precipitate which ammonia forms with acid phosphate 
of ferrous oxide, re-dissolyes in excess of ammonia. (A. Vogel.) 

G. Phosphate of Ferric Oxide and Ammonia. — Ferrico-ammonic 
Fhotphate. — White phosphate of ferric oxide dissolves, with a brown 
colour, in aqueous ammonia, which may afterwards be expelled by evapo- 
ration. (Dobereiner, Schw» 26, 271 .) 

IT G'. Ammoniacal Azophosphate of Ferric Oxide. — Ferric 
azophosphate (p. 259) dissolves in ammonia, forming a red solution from 
which the iron-salt may be again precipitated by the addition of an acid. 
The ammoniacal solution carefuUy evaporated oyer the water-bath, yields 
a dark red mass very soluble in water, but showing no disposition to 
crystallize. When treated with water, after being perfectly dried, it 
separates into two portions, the one soluble containing ammonia, and 
giving a characteristic precipitate when treated with an acid — the other 
having the form of micaceous plates of the colour of ferricyanide of 
potassium : these appear to be chiefly sesquioxide of iron. (Gladstone, 
Chem. Soc. Qu. J. 8, 146.) H. 

H. Sulphate of Ferrous Oxide and Ammonia. — FerroBtMimmonie 
Sulphate, — To form this salt, a solution of 66 pts. (1 At.) of sulphate of 
ammonia and 138 pts. (1 At.) of green vitriol is left to crystallize. On 
mixing equal measures of the saturated solutions of green vitriol and 
sal-ammoniac, the same salt likewise crystallizes out gradually, while 
protoohloride of iron and ammonium remains in solution. (A. Vogel.) 
—The crystaL9=NH«O^SO*+F60|SO'+6 Aq. are isomorphous with 



262 IRON. 

those of sulpliaie of magnesia and ammonia (III. 248) and many btheis; 
Fig, 84. (Mitscherlich; comp, Marx, Schw. 54, 465.) The crystals when 
purified by re-crystallization, are transparent, and colourless, very hard, 
and effloresce somewhat above 1 00^. When heated, they swell np to a 
white mass, without fusing, and give off water, ammonia, and sulphate of 
ammonia. Oil of vitriol abstracts their water, and makes them opaque. 
They are much less soluble in water than green vitriol. (A. Vogcl, 
J, pr. Chem. 2, 192.) 

I. Sulphate op Ferric Oxide and Ammonia. — Ferrico-ammonic 
Sulphate. — a. Basic, — When a solution of iron in a dilute mixture of 
sulphuric aud nitric acids is exposed to the air, this double salt is pre- 
cipitated in the form of an ochre, which, when heated, gives off water and 
ammonia, and afterwards sulphurous acid — ^is not decomposed by caustic 
potash — and is but very sparingly soluble in hydrochloric acid. (Ber- 
zelius.) 

6. Containing BisulpJuxte of Ferric Oxide. — Formed by adding 
ammonia to a solution of ammonia-iron-alum till the precipitate begins 
to be permanent, and leaving the dark brown mixture to evaporate 
spontaneously. — Transparent, yellowish-brown, short, regular, six-sided 
prisms, soluble in 2*4 pts. of cold water. (Maus, Fogg, il, 79.) 

Mans. 

2NH» 34 .... 10-43 lO'SO 

Fe^O' _ 78 .... 23-92 23-75 

4S0» 160 .... 49-08 4920 

6HO 54 .... 16-57 16*75 

3(NH*0, S03) + Fe20», 2SO» + 4Aq 326 .... 10000 ZZ 10000 

c. Containing Terstdpkate of Ferric Oxide. — Crystallizes from a 
mixture of sulphate of ammonia and tersulphate of ferric oxide in 
colourless, regular octohedrons and cubo-octohedrons {Figs. 2 and 4), the 
specific gravity of which, according to Kopp, is 1-712. They are soluble 
in 3 parts of water at 15^ (Forchhammer.) The. yellow colour which 
the salt occasionally exhibits, arises from excess of the iron-salt, and 
disappears on recrystallization. (Forchhammer; Ann. Fhil. 5, 406j Bor^ 
zelius, AJhandlingar £. 3; also Scher. Ann. 7, 228 j Mitscherlich.) 

NH» 17 .... 

Fe20» 78 .... 

i APO* 

4S03 160 .... 

25HO 225 .... 





ForcbbAmmer. 


3-54 




16-25 


16-470 


• 


0-260 


33-33 


34-596 


46-88 


43-480 



NH*0,SO3+Fe?O»,3S0» + 24Aq. 480 .... 100-00 

K. Hydrgbromate op Ammonia containing Sesquibromide op 
IkON. — An aqueous solution of 3 pts. sesquibromide of iron and 2 pts. 
hydrobromate of ammonia yields, on gentle evaporation, light red needles 
united in bundles. These crystals, when dissolved and treated with 
ammonia, yield 2*47 per cent, of ferric oxide. They do not become 
moist by exposure to tne air; are easily soluble in water; and separate 
from the solution, on evaporation, with a diminished amount of iron, 
while a mother-liquid richer in iron remains. (Lowig.) 

L. Ammonio-protochloridb op Iron. — Protockloride of iron absorbs 
ammoniacal gas with avidity, and swells up to a white. powder which 



SESQUICHLORIDE OF IRON AND AMMONIUM. 263 

gives np its amrooDia when heated^ but on the addition of water, is partly 
resolved into bydrochlorale of ammonia and hydrated ferrous oxide. 
(Faraday.) 

M. PROTOCHLORIDE OP Iron AND Ammonibm. — Ferroso-ammonic 
Chloride. — By boiling iron filings with a saturated solution of sal- 
ammoniac in a close vessel — whereupon hydrogen and ammouiacal ga^'are 
evolved — and leaving the solution to crystallize by cooling. (Hisinger & 
Berzelius, Gilb. 27, 273.) — 2. By mixing saturated solutions of green vitriol 
and sal-ammoniac in equal volumes — allowing the ferroso-ammonic sul- 
phate to crystallize ont — ^ponring ofif the remaining liquid and evaporating 
it to the crystallizing point — and separating the crystals mechanically 
from the sal-ammoniac which crystallizes out with them. (A. Vogel, J. pr, 
Ckem. 2, 192.)— 3. An aqueous solution of 1 pt. protochloride of iron and 
4 pts. sal-ammoniac, prepared hot and filtered, is set aside for 24 hours in 
a closed vessel — and the resulting crystals dried as quickly as possible, 
and kept in stoppered bottles. ^Winckler, Reperi, 59, 171.) — Prepared by 
(1)-: bluish-green crystals, whicn, when exposed to the air, become covered 
with hydrated ferric oxide, and whose aqueous solution is not precipitated 
by ammonia, unless the air has access to it. (Hisinger & Berzelius.) — 
By (2): lemon-yellow, transparent octohedrons which neither deliquesce 
nor effloresce in the air — give off sal-ammoniac when heated — and are 
easily soluble in water, but not in alcohol. (A. Vogel.) — By (3): trans- 
parent and colourless rhombohedrons, which have a sharp saline and 
afterwards astringent taste, contain 11*2 per cent, of ferrous chloride, 
turn yellowish in the air, and are easily soluble in water. (Winokler.) 

N. AsfiiONio-flESQUicHLORiDB OF Irok. — Sesquichlorido of iron 
slowly absorbs ammoniacal gas at ordinary temperatures, producing a 
slight disengagement of heat, but without alteration of external appear* 
i^nce. Part of the compound volatilizes undecomposed when heated; the 
rest leaves protochloride of iron. It deliquesces in the air, but less 
quickly than pure sesqnichloride of iron. When thrown into water in 
considerable quantities, it dissolves with a hissing noise; the solution is 
4ark red and transparent. (H. Rose, Fogg, 24, 302.) 

H. Rose. 

NH» 17-0 .... 9-59 9 

FeH:P 160-2 .... 90-41 91 

NH*,Fe»CP 177-2 .... 10000 ZZ 100 

0. Sesquichlorjdb of Iron akd Ammonium. — Ferrico-ammonic 
Chloride, — 1. A solution of sal-ammoniac in a large excess of ferric 
hydrochlorate, when evaporated over oil of vitriol within a receiver con- 
taining air, yields garnet-coloured crystals belonging to the oblique 
prismatic system, which may easily be mistaken for regular octohedrons; 
they are not decomposed by water like the corresponding compound of 
chloride of potassium. (Fritzsche, J. pr. Chem. 18, 484.) — 2. By slowly 
evaporating a mixture of this nature, the author obtained very deli- 
quescent rectangular octohedrons, having two of the basic edges and four 
of the basic angles truncated. 

Fritzsche. 



2NH< 

2Fe 


36 

54 


• ••• 

• «•• 
■ •«• 


12-63 

18-95 

62-10 

6-32 


19-47 


5C1 


177 


61-66 


2HO 


18 











2NH*C1 + Fo*CP + 2 Aq. 285 ..,. lOO'OO 



264 IRON. 

Or: 

2NH». Ha ^ 106-8 37-47 

FeWP 160-2 56-21 

2HO 18-0 6-32 

2(NH«,HCl),Fe»CP+ 2Aq. 285-0 10000 

P. Sal-ammoniac containing Sesquichlobide of Iron. — A 
Bolntion of from 3 to 24 parts of sal-ammoniac and 1 part of sesqui- 
cliloride of iron in water yields on evaporation, aurora-red transparent 
crystals. According to Geiger, these crystals are acute rhombohedrons 
when they contain a medium quantity of iron, but obtuse when the 
proportion of iron is either very small or very large; according to Marx 
also (Schw, 54, 304), they appear to be made up of a great number of 
small cubes not quite regularly CTOuped together, whereby the cubical 
shape is somewhat altered. (Gm.) — The quantity of iron is small and 
variable. If 24 parts of sal-ammoniac are used to 1 part of the ferric 
chloride, the crystals contain 0*85 per cent, of ferric chloride; if 14 parts 
of sal ammoniac are used, they contain 1*93; and with 3 sal-ammoniac, 
they contain 5*12 per cent, of ferric chloride. The mother-liquor of the 
last-mentioned crystals yields, on further evaporation, brown-red crystal- 
line granules, containing 5*75 per cent of ferric chloride. (Geigcr.) 
When 10 pts. sal-ammoniac have been used with 1 pt. ferric chloride, 
the crystals contain 0*86' per cent, of the latter. (Winckler, ReperL 
67, 155.) The crystals, when heated, become yellow and opaque, and 
evolve, first sal-ammoniac, and afterwards ferric chloride. They dissolve 
in 3 parts of cold water; those in which the proportion of ferric chloride 
does not exceed 5*12 per cent., become moist only in damp air; those 
which contain 5*75 p. c. Fe'CP, become moist even in dry air. (Geiger, 
Repert. 13, 422.) When their aqueous solution is evaporated, sal- 
ammoniac crystallizes out, nearly pure at first, but afterwards continually 
richer in iron, being first yellow and then red, and there remains a 
mother-liquid richer m iron. 

To these mixtures of ferric chloride and sal-ammoniac, belong the 
Feri'uginotis Flowers of Sal-ammoniac, Flores Salis-ammoniaci martiaU^ 
These are obtained: — 1. By subliming 16 pts. sal-ammoniac with 1 pt. 
ferric oxide, whereupon ammonia is evolved; or with 1 pt. iron filings, 
in which case hydrogen is set free and protochloride of iron and ammo- 
nium is produced, the latter, however, if the air has moderately free 
access to it, is converted into sesquichloride of iron and ammonium, while 
ferric oxido is left behind. — 2. By subliming a mixture (obtained by 
evaporation) of 12 parts sal-ammoniac and hydrochlorate of ferric oxide 
prepared from 1 part of iron filings. — 3. By dissolving 16 pts. sal-ammo- 
niac and 1 pt. ferric chloride in water and evaporating to dryness. Some 
pharmacopoDias, however, direct the preparation of the crystals above 
described. Yellow saline mass, which is yellower and more deliquescent 
in proportion as it is richer in iron. 



Iron and Potassium. 

A. Alloy op Iron and Potassium. — Formed in the preparation of 
potassium by method No. 2 (III. 5), when pieces of iron happen to be 
situated at the lower end of the gun-barrel where it projects from the 
furnace. — ^Whiter than iron, malleable, and so soft tliat it will often take 



FERRATE OF POTASH. 265 

impressions from tHe nails; more fosible than iron. Oxidizes in the air; 
effervesces with water and with aqueous acids. (Gay-Lussac & Th6nard.) 

B. Ferbite op Potash. — 1 . When hydrate of potash is fused in an 
iron crucible, and the whole digested in water after cooling, a portion of 
ferric oxide (ferrous acid) is dissolyed together with the potash.— <* 
2. When recently precipitated hydrate of ferric oxide is boiled for an 
hour with strong caustic potash, a very pale yellow liquid is obtained 
containing a small portion of ferric oxide. (Ghodnew, J, pr, Ghem. 
28, 221.) 

C. Ferrate op Potash. — Becquerel {Ann, Ohim. Fhyz, 51, 105) 
found that ferric oxide ignited in a silver crucible with from 4 to 6 times 
its weight of potash-hydrate, dissolved in the potash, but was separated 
again, with evolution of oxygen, when the potash was dissolved in water; 
this escape of oxygen was attributed by Becquerel to the presence, not of 
ferric acid but of peroxide of potassium. — Ferrate of potash is formed 
when iron or ferric oxide is heated to redness with nitre or peroxide of 

fotassium, or — if air has access to the mixture — ^with hydrate of potash, 
t is also produced by the action of chlorine on ferric oxide diffused 
through a strong solution of potash (Fremy, J, Pharm, 27, 1^7; also 
J. pr, Chem. 26, 108); and by galvanic action. H The existence of 
ferric acid appears to have been known to Stahl, who observed that when 
iron is calcined with nitre and the mass digested in water, the caustic 
alkali produced by the calcination of the nitre takes up part of the iron, 
forming an amethyst or purple solution; also, that if a very dilute solution 
of iron in nitric acid be poured by small portions at a time into very 
strong caustic potash and the liquid agitated, the iron dissolves and 
imparts a blood-red colour to the liquid. — Subsequently, Eckeberg(Jron^Z. 
Vetenfk, Handl, 1802, p. %%', also Scher, J, 9, 607) on fusing ^ulolinite 
with caustic potash, obtained an alkaline solution which had a dark red 
colour and deposited a brick-red compound of iron and lime. And in a 
note he adds that the red colour is not due to manganese, for even iron 
alone can dissolve in caustic potash and produce the most beautiful 
purple colour, provided it has been previously roasted. {J, pr. Chem. 
32, 448; comp, Kopp, GesckichU d, Ghem. 1, 192.) IT 

Preparation of the dry saU, — 1. By igniting ferric oxide very strongly 
for some minutes with nitre and hydrate of potash. If the heat is too 
low, nitrite of potash remains undecomposed, and then, on the addition of 
water, reduces the ferric acid to the state of sesquioxide. (Fremy.) — A 
mixture of 1 part of finely pulverized ferric oxide and 4 parts of nitre is 
introduced into a crucible capable of containing double the quantity; the 
cover luted on tight, but in such a manner as to leave an exit for the gas; 
and the mixture heated — ^for an hour if the quantity is 6 ounces, for a 
shorter time if it be smaller — to a bright red heat, but not higher, 
(Denham Smith, Phil, Mag. J, 23, 217.) — ^2. By igniting iron-filings 
with nitre. (Fremy.) — An intimate mixture of 1 pt. finely divided iron 
and 2 pts. dry nitre is introduced into a capacious crucible kept at a dull 
red heat, and the crucible removed from the furnace as soon as the 
mixture begins to deflagrate and form a white cloud, an effect which 
begins at one point and quickly extends throughout the whole mass. If 
the temperature is too high, the compound is decomposed as soon as 
farmed. (H. Trommsdorff, N. Br, Arch, 29, 104.) If the crucible is too 
hot, the nitre fuses without deflagrating. The mass must then be poured 



i66 IRON. 

into an iron mortar and again introdnced into the cmcible after cooling. 
The crucible should therefore be heated so as to exhibit perceptible 
redness only at the bottom and a few inches aboTC, and the mixture 
should be thrown into the middle and somewhat to the side: the defla- 
gration — which is unattended with danger — ^then takes place in a few 
seconds with a bright glow and intumescence of the mass. The crucible is 
removed from the fire either during or immediately after the deflagration, 
and the soft, somewhat friable mass taken out with an iron spoon. As, 
however, ferrate of potash thus obtained is contaminated with nitrite, 
the red solution which it forms in water quickly loses its colour. (Wack- 
enroder, iV, Br. Arch. 33, 41.) — 3. By igniting ferric oxide for a consi- 
derable time with hydrate of potash. (Fremy.) — The red-brown or 
reddish, highly deliquescent mass thus obtained is quickly pulverised, and 
preserved in dry, well-stopped bottles. 

Aqueous Ferrate of Fotcuh — 1. Formed by dissolving the dry salt in 
cold water. Since the act of solution is attended with evolution of heat, 
by which a portion of the salt is decomposed, it is necessary to nse ice- 
cold water; there is always, howeyer, a slight evolution of oxygen gae, 
probably arising from peroxide of potassium. The solution most be 
separated from the undissolved portion by subsidence and deeantation, 
not by filtering. (D. Smith.) — 2. By passing chlorine gas through a yery 
strong solution of potash in which ferric oxide is diffused, till the oxide 
dissolves and forms a red solution. (Fremy.) When 5 parts of hydrated 
ferric oxide, recently precipitated and dried between bibnlous paper, 
10 parts of hydrate of potash, and 16 of water are used, and chlorine 
rapidly passed through the solution, the oxide quickly dissolves in the 
liquid, which gradually rises in temperature, and deposits chlorate of 
potash on cooling; if too much water or too much ferric hydrate is used, 
the liquid remains colourless. (Wackenroder.) The chlorine must not be 
in excess, otherwise it will decompose the salt. (H. Rose.) — J). Poggen- 
dorfi^s process consists in passing the positive electricity of a six-pair 
Grove's battery (I. 422) for 24 hours, through an electrode of English 
cast-iron, into a solution of caustic potash concentrated as much as 
possible* and surrounded with ice; in that solution there is likewise 
immersed a clay cylinder filled with caustic potash, and the negative 
electricity is conducted into the latter liquid by means of a platinum 
plate. If a more dilute solution of potash is used, the resulting prepare 
tion is less permanent. No oxygen gas is evolved on the iron plate, 
excepting just at the beginning of the action or a little after; if the 
current be long continued, microscopical crystals of ferrate of potash are 
deposited on this plate; a small quantity of iron collects on the platinum 
plate. (H. Rose, Fog^. 59, 315.) 

Aqueous ferrate of potash is of a deep amethyst- red or cherry- red 
colour, and pervious to light only when in yery thin strata. — The solution 
when left to stand for some time, loses its colour, gives off oxygen gas, 
and yields a precipitate of hydrated ferric oxide, the decomposition taking 
place the more quickly as the solution is warmer and more dilute. 
(Fremy.) The concentrated solution obtained by (2), if kept in close 
yessels, does not decompose completely, eyen in the course of seyeral 
mouths, but leaves a red residue when evaporated. (D. Smith.) At 100% 
the decolorization is instantaneous. (Fremy.) The concentrated solution 
obtained by (3) sustains a boiling heat without decomposition, but after* 
wards deposits ferric oxide more quickly than if it had not been boiled; it 



FERRATE OF POTASH, 267 

18 altogetlier more permanent than that obtained by (2), retains its 
deep red-colour for months, and deposits but little ferric oxide all the 
while. Dilution with various potash aud soda-salts produces less tendency 
to decomposition than dilution with pure water. When the solution, 
after long standing, has deposited all its ferric oxide, it exhibits a green 
colour, arising from manganate of potash formed from manganese contained 
in the cast-iron. (H. Rose.) — Sulphuric or nitric acid forms a double salt 
of ferric oxide and potash, with liberation of oxygen gas (Fremy); hydro- 
chloric acid likewise forms a double salt, with evolution of chlorine 
(D. Smith); a smaller quantity of acid causes a precipitation of ferric 
oxide (Fremy). With zinc-salts the solution evolves oxygen ; from man- 
ganese and nickel-salts it precipitates the peroxides. (Smith.) Other 
heavy metallic salts and alum likewise decolorize the liquid, the base 
being precipitated together with ferric oxide. (Wackenroder.) — The com- 
pound is quickly decomposed by de-oxidizing agents. Sulphurous acid 
forms sulphate of potash and precipitates ferric oxide. (H. Rose.) Sul- 
phuretted hydrogen colours the solution (2) dark green by forming sul- 
phide of iron (Wackenroder); the concentrated solution (3) is converted by 
the same reagent into a black mass, which forms a deep green liquid with 
a large quantity of water. (H. Rose.)-— Ammonia and all ammoniacal salts 
decompose the compound, because the ammonia which is evolved reduces 
the ferric acid to ferric oxide. (Wackenroder, H. Rose.) — All organic 
substances act in the same manner; hence the solution cannot be filtered 
through paper. (Fremy.) Oxalic acid mixed with the solution gives off 
carbonic acid and oxygen gas. (D. Smith.) Alkaline racemates, tartrates, 
and malates quickly decolorize the liquid, without precipitating ferric 
oxide; alkaline citrates act very slowly and occasion a precipitation of 
ferric oxide. Oxalate, acetate, formiate, and benzoate of potash decolorize 
the liquid as slowly as the inorganic salts of potash ; and succinate of 
potash acts still more slowly. Alcohol (with formation of aldehyde, 
apparently) sugar, and white of egg, decolorize it quickly, the former 
with, the latter without, precipitation of ferric oxide. (H. Rose.) Ferro- 
cyauide of potassium likewise exerts a decolorizing action. (Wacken- 
roder.) 

The solution (1) if boiled till completely decolorized evolves 25*67 pts. 
oxygen gas for every 100 pts. of precipitated ferric oxide. [This is 
equivalent to 10*01 pts. (not quite 1^ At.) oxygen to 39 pts. (| At.) 
ferric oxide.] Since the liquid can only be separated from the undissolved 
oxide by decantation, it is possible that some portion of the oxide still 
remained suspended in it, in which case, the proportion of oxygen to the 
ferric oxide would come out too small. On the supposition that ferric 
acid is FeO', 12 pts. of oxygen should be evolved for every 39 pts. of 
ferric oxide. (D. Smith.) — By passing sulphurous acid gas through the 
Bolutiuu (3) till the colour is destroyed, and determinin<; the quantity of 
ferric oxide precipitated and sulphuric acid produced (by supersaturating 
the^iiltrate with hydrochloric acid and precipitating with chloride of barium) 
349*8 pts. (3 At.) of sulphate of baryta were found to correspond, in 
different experiments, to the following quantities of ferric oxide: 73*1; 
78*3; 81*9; therefore approximately 78 pts. (1 At.) Hence ferric acid^ 
FeO^; and when it is decomposed by sulphurous acid, 3 At. sulphuric 
acid are produced for each atom of ferric oxide. (U. Rose.) 

2Fe03 + 3S05 = Fe^O* + 3S0', 
When 1 pt. ferric oxide is ignited as above (p. 265) with only 2 pts. nitrate 



268 LEAD. 

of potash (or better with nitrate of soda), and the mass digested in water, 
a beautiful green solution is obtained like that of mineral chameleon, and 
always mixed with the red salt: the latter, however, is soon decomposed, 
whereas the green salt may be kept in close vessels for a longer time. 
This green salt appears to contain an acid with a smaller quantity of 
oxygen. Chlorine colours the solution red; acids likewise redden the 
liquid, with evolution of oxygen, and afterwards decolorize it. The green 
liquid may be passed through paper without decomposition, but it ia 
decomposed by prolonged contact with organic substances. (D. Smith.) 



D. Carbonate op Feario Oxide and Potash. — a. Ferrico-potassie 
CarhoncUe. — StakVs Alkaline Tincture of Iron. — When a ferric salt is 
supersaturated with strong carbonate of potash, the precipitated ferrie 
hydrate is re-dissolved and forms a blood-red solution. This solution is 
decomposed, with precipitation of ferric hydrate, both by heat, and by- 
dilution with water or with caustic potash. (Hausmann, Scher. J, 4, 576; 
Proust, N. Gehl. 3, 560; Dobereiner, Schw. 9, 1.) Freshly precipitated 
ferric hydrate is not soluble in strong carbonate of potash, so that the 
presence of the potash-salt formed at the same time appears to be neces- 
sary to the solution. (Grotthuss, Schw, 30, 71.) 

E. BoRiDE OF Iron and Potassium.— The three substances combine 
at a white heat, and form a blackish mass which exhibits the metallic 
lustre, conducts electricity, effervesces slightly in water, and when treated 
with hydrochloric acid, yields ferrous oxide and boracic acid. (H. Davy.) 



F. Sulphide of Iron and Potassium. — a. When sulphide of anti- 
mony is ignited with iron, carbonate of potiush, and charcoal, an easily 
fusible slag is obtained. TBerthier.) 

h. Iron filings placea in contact with solution of potassic liver of 
sulphur, turn black and impart a green colour to the liquid. ( Vauquelin.) 

c. The concentrated solution of ferrate of potash obtained by (3) is 
converted by sulphuretted hydrogen into a black mass probably consisting 
of KS,FeS^; this forms a dark green liquid with water, which remains green 
even when very much diluted. The solution remains permanent in the lur 
for a long time. Continued boiling decomposes the concentrated solution, 
with separation of sulphide of iron; the dilute solution undergoes no 
alteration, excepting that it acquires a transient brown tint every time it 
is heated. (H. Rose, Fogg, 59, 320.) 

G. Sulphate op Ferrous Oxide and Potash. — Ferroso-potassic 
^w/pAafe.— KO,SO'+FeO,SO»+6 Aq.— Formed by dissolving iron-filings 
in a warm aqueous solution of bisufphate of potash. Greenish crystals, 
which have the form of sulphate of magnesia and ammonia, refract light 
doubly, have a rough taste, and fall to pieces when exposed to the air. 
(Link, CrelL Ann. 1796, 1, 30; Mitscherlioh; Brewster, Schw, 33, 344.) 

H. Sulphate of Ferric Oxide and Potash. — Ferrico-potatm 
Sulphate. — a. Yellow Iron-ore. Ochre-yellow, homogeneous, massive 
plates; sp. gr. 2v8...2-9; fracture varying from flatly conchoidal to 
earthy. When heated, it turns red, evolves water and afterwards sul- 
phurous acid; gives up nothing to boiling water; slightly soluble in 
hydrochloric acid, more readily in aqua-regia. {Rammebbeig, Pogg. 43, 
134.) 



FERRICO-POTASSIC SULPHATE. 269 

Teliow Iron-ore, from Kolostrak. Pammelsbci^. 



KO 


47-2 




7-37 

48-78 ;;; 

81-25 
12-65 


7-88 


CaO 

4Pe20s 


8120 


0-64 
46-74 


6S0» 

9H0 


200-0 

81-0 


8211 
13-56 



KO,S03 + 4(Fe»03,S03) + 9Aq. 640*2 ... 10000 100-93 

h. Remains in the form of a pale yellow powder when the salt c is 
treated with hot water. (Anthon.) 

Anihon. 

K0,80» 87-2 ... 8-09 80 

6Fe«0» 4680 ... 4845 414 

9S0> 860-0 ... 33-42 85*6 

18H0 1620 ... 1604 150 

KO,SO» + 8(2Pe«O8,3S03) + 18Aq. 10772 ... 100*00 ~, lOO'O 

c. Formed hy adding potash to a solation of potash-iron-alnm till a 
permanent precipitate begins to form — or rather by adding a smaller 
quantity of potash, so that a considerable aaantity of iron-alum may 
remain undecomposed — and leaving the dark liquid to evaporate freely in 
a shallow dish. — ^Yellowish-brown, transparent, regular six-sided prisms, 
shortened into tables ; when heated, they give off their water of crystal- 
lization, but retain their form. Their solution in cold water, 6 parts of 
which are required to dissolve them, is soon decomposed — unless it likewise 
contains potash-iron-alnm — into precipitated disulphate of ferric oxide, 
and iron-alum which remains in solution. (Maus, Fogg. 11, 78.) — The 
same salt has been accidentally obtained in the preparation of iron-alum : 

1. A solution of 78 pts. ferric oxide, 147 oil of vitriol, and 87*2 sulphate 
of potash, deposited — ^partly during concentration— dark brown crystal- 
line crusts, which gave off water and assumed a red-brown colour at a 
temperature below redness, and evolved sulphnric acid at a white heat, 
leaving a residue of ferric oxide mixed with sulphate of potash. The salt 
dissolves in 12-75 parts of water at 10°; but, when heated with water, it 
is resolved into salt 6, and a red-brown solution, which deposits, on evapo- 
ration, first the salt c and then iron-alum. (Anthon, Repert, 76, 361.) — 

2. If a boiling solution of sulphate of potash be added to an over-concen- 
trated solution of ferric sulphate, a small, greenish-yellow, crystalline 
precipitate is produced, having the composition given below; after several 
days' standing, however, it disappears again, with formation of iron-alum. 
Also, when crystallized iron-alum is dissolved in a small quantity of hot 
water, the greenish-yellow salt is deposited first. (W. Richter, N, Br, 
Arch. 23, 316.) 

2K0 94-4 

Fe"0« 780 

4S0> 1600 

6H0 540 

2(KO,SO') + Fe"0',2S05 + 6Aq. 886-4 ... 10000 ... 100-0 ... 99*7 ... 1000 

(L When carbonate of potash is added, with agitation, to an aqueous 
solution of tersulphate of potash, as long as no permanent precipitate is 
formed, and the dark brown liquid (which becomes turbid when filtered 
as well as when heated) is mixed with a large excess of alcohol, a light 
reddish-yellow precipitate is formed^ which must be washed with alcohol. 





MftUB. 


Anthon. Bichter. 


24-43 


... 28-1 


... 20-5 ... 22-2 


20-19 


... 20-8 


... 21-2 ... 21-6 


41-41 


... 41-7 


... 42-6 ... 421 


18-97 


... 14-4 


... 15-4 ... 14-2 



270 IRON. 

This precipitate; vhile yet moist, is soluble in water, but after it is dry, 
water decomposes it, leaving basic sulphate of ferric oxide undissolved. 
The aqueous solution deposits a light yellow ochre on standing, and more 
quickly on boiling, losing at the same time the greater part of its colour. 
(Soubeiran, Ann. Ckim. Pht/s. 44, 329.) 

Soubeiran. 

2X0 94-4 ... 1115 11-4 

SFe^Oa 234-0 ... 2764 266 

880' 8200 ... 87-81 870 

22HO 198-0 ... 23-40 240 

2(KO,S03) + 8(Fe^05,2S03) + 22Aq. 8464 ... lOO'OO ^^7^^^ 990 

e. Fotasfhiron-alum, — 78 parts of ferric oxide are dissolved in 147*2 
pts. oil of vilriol mixed with water and heated, and 87'2 pts. sulphate of 
potash added thereto, or 276 pts. (2 At.) green vitriol mixed with 49 pts. 
oil of vitriol, are oxidized by nitric acid at a boiling heat, and 87*2 pts. 
sulphate of potaeh added to the liquid; or, according to Heintz^s method, 
10 parts of pounded crystals of green vitriol are heated with 4 parts of 
nitre and 5 of sulphuric acid, till no more nitrous acid is evolved, — then 
dissolved in a fourfold quantity of water at 80°, and filtered. When the 
concentrated solution is left to stand for some time at a temperature of 0^, 
or somewhat above, the alum crystallizes out; and by taking out the 
crystals first obtained, and putting them in again after evaporating the 
liquid a little further, very large crystals may be obtained. The mother- 
liquid, mixed with a small quantity of sulphuric acid and evaporated, 
deposits a white granular powder or crystalline crust, consisting of iron- 
alum with only 8*5 or 9 per cent. (3 At.) water of crystallization; this, 
when quickly washed with cold water and then dissolved in warm water, 
yields more octohedrons. If the remaining mother-liquid be still further 
evaporated till nothing remains but a saline mass mixed with fluid, and 
this majBS quickly washed, iron-alum is left, containing only 2-9 to 3*3 p.c. 
(1 At.) water. Commercial iron-alum contains a large quantity of 
alumina. (W. Heintz, Popg, 55,331.) 

Regular octohedrons. Pale violet. (Richter, Heintz, Gmelin.) 
Colourless, according to other authorities. 

Iron-alum, when exposed to the air, becomes slowly covered with a 
white powder. (W. Richter.) It fuses in its water of crystallization, 
afterwards gives oflf its water, and is converted into a yellowish- white, 
spongy mass resembling burnt alum. When very strongly ignited, it 
fuses, gives off 24*4 per cent, of sulphuric acid, and leaves a mixture of 
15-1 per cent, ferric oxide and 17 p. c sulphate of potash. (W. Richter, 
lit pert 76, 361.) Iron-alum is resolved by heat into the salt c, tersul- 
phate of ferric oxide, and free sulphuric acid. 

2(KO,S03 + FeW,3S08) = [2(KO,S08) + Pe203,2S08J + FeSQS.SSO^ + SO*. 

When, therefore, pulverized iron-aliim is dried over oil of vitriol between 
60" and lOO'', it first becomes moist and then leaves a brownish-yellow 
powder, which, if treated with water, will perhaps yield a few more 
octohedrons; but these ate probably reproduced alum. (Heintz.) When 
iron-alum is dissolved in a small quantity of hot water, the greenish- 
yellow salt c is likewise dej^osited at first, but it is afterwards reconverted 
mto alum and redissolved. (Richter.) Iron-alum dissolves in 5 parts of 
water at 12-5"'. (Anthon.) 



IRON AND SODIUM. 871 



KO 47-2 ... 9-42 

Fe20» 780 ... 15-66 

4S0« 1600 ... 81-92 

24HO 2160 ... 48-10 



AnthoiL 




Ricliter. 


9-2 


« •• 


10-8 


161 


••• 


14-9 


82-2 


... 


80-9 


43-5 


... 


48-5 



KO,B05 + Fe=0',880» + 24Aq. 501-2 ... 100-00 100-0 ... 99*6 

I. Protochloride of Iron and Potassium. — Ferroso-potassic 
Chloridt, — When the conceQtrated solutions of the two metallic chlorides 
are mixed and the mixture cooled or gently evaporated^ bluish-green^ 
hjdrated crystals are obtained. (Berzelius ) 

K. SBSQunm^oRiDE of Iron and Potassium. — Ferrico-potassio 
Chloride, — A solution of chloride of potassium in excess of ferric hydro- 
chlorate evaporated under a bell-jar over oil of vitriol, yields small 
yellowish-red crystals belonging to the oblioue prismatic system. A small 
quantity of water extracts chloride of iron trom them and leaves crystals 
of chloride of potassium undissolved, as may be seen by examination with 
the microscope. A larger quantity of water dissolves the whole; but on 
evaporation, colourless crystals of chloride of potassium separate out first, 
and afterwards coloured crystals of the ferrico-potassic chloride; and 
at this degree of concentration, the crystals of chloride of potassium 
re-dissolve without any warming or stirring, and are re-converted into 
crystals uf ferrico-potassic chloride. (Fritzsche, J. pr. Chem. 18, 483.) 





CryUallized. 


Fritzsche 


2KC1 


149-2 .... 45-57 .... 


.... 44-72 


2Fe 


64-0 .... 16-49 .... 


.... 17-17 


3C1 


106-2 .... 32-44 .... 


.... 31-39 


2HO 


18-0 .... 6-50 





2KCl,Fe»Cl' + 2Aq 327-4 .... 10000 

L. Protofluoridb op Iron and Potassium. — Ferroso-potassic 
Fluoride, — KF,FeF. — Precipitated on mixing hydroflnate of potash with 
solphate of ferrous oxide. (Berzelius.) 

M. Sesquifi^oridb op Iron and Potassium. — Fennco-potassic 
Fluoride, — a. Terbasic, — Formed by dropping aqueons sesquifluoride of 
iron into excess of fluoride of potassium.-—^. Bibasic, — By the contrary 
process. — In both cases, small colourless crystals are obtamed somewhat 
soluble in water, especially in hot water. (Berzelius, Fogg. 4, 129.) 





a, 3KF,Fc2F«. 




6. 2KF,Fe2F«. 


Berzelias. 


3K 


.. 117-6 .... 41-44 


2K 


78-4 .... 34-71 ... 


33-88 


2Fc 


540 .... 19-03 


2Fe 


540 .... 23-90 ... 


24-06 


6F 


.. 112-2 .... 39-53 


6F 


93-5 .... 41-39 





283-8 .... 100-00 225-9 .... 100-00 



Iron and Sodium. 

A. Fbrrite op Soda. — ^78 pt-a. (1 At.) of ferric oxide mixed with 
excess of ignited carbonate of soda, drive ofl*, at a red-heat, 23-19 (a little 
more than 1 At.) carbonic acid, and form a difficultly fusible mixture. 
This mixture, when cool, is liver-coloured— has a waxy, conchoidal 



272 IRON. 

fracture — and takes up carbonic acid from tHe air, becoming red-browa 
and dull. Water either hot or cold dissolves out the caustic soda 
(together with the excess of carbonate), and leaves ferric oxide free from 
soda: the latter is brown-black after drying, and dissolves easily in dilute 
hydrochloric acid, but a small quantity of magnetic oxide (about 
2'1 per cent, of the ferric oxide) usually remains undissolved. (Count 
Schaffgotsch, Pagg. 43, 117.) 

B. Carbonate of Ferric Oxide and Soda. — ^Analogous to carbonate 
of ferric oxide and potash. 

C. and D. — With Borax^ ferric oxide yields upon charcoal in the 
inner flame, a dark bottle-green glass, which, by more complete reduction 
to the state of ferrous oxide, acquires a lighter bluish-green colour, and, 
if the quantity of iron is but small, appears colourless after cooling. 
The reauction is accelerated by addition of tin. In the outer flame, a 
yellowish-red glass is produceil, which on cooling becomes yellow and 
afterwards colourless, if the quantity of ferric oxide is but small, but 
remains yellow if it be larger. — Microcosmic Salt behaves like borax. 
(Berzelius.) 

% E. PrROPHosPHATE OP Ferroub Oxide and Soda. — Ferrato-godic 
Pyrophosphate, — Exists only in solution, and when exposed to the air, 
turns red and yields a deposit. Sulphuretted hydrogen colours it brown, 
and sulphide of ammonium precipitates it completely. (Persoz, Ann, 
Pharm. 65, 170.) 

P. Pyrophosphate of Ferric Oxide and Soda. — Ferrico-sodie 
Pyrop?iosphate, — Obtained by boiling pyrophosphate of ferric oxide with 
a quantity of pyrophosphate of soda not sufficient to dissolve it, 
and precipitating with alcohol. (Fleitmann & Henneberg, Ann. Pharm. 
65, 390.) — Colourless and easily soluble. The solution may be evaporated 
to a syrupy consistence without becoming turbid; but is partially decom- 
posed thereby, like the alumina-salt. No turbidity or colour shows itself 
even after the solution has been left to evaporate spontaneously for a 
month. When treated with sulphuretted hydrogen, it assumes the colour 
of catechu, without yielding a deposit of sulphur; and on the addi- 
tion of sulphide of ammonium, a deep green colour is produced. A 
precipitate likewise appears after a while, but it re-dissolves on being 
washed and yields a greenish-brown solution. The formula of this 
salt is P»40'*,Fe»0»-|-y*0«,2NaO)-|-a:Aq. (Persoz), or 2Fe«0»,3PO«-h 
2(2NaO,PO*)+7 Aq. (Fleitmann & Henneberg.) IT 

Fleitmann & 
Henneberg. 

2?^(y 156 .... 22-29 -.. 2242 

4NaO 124 .... 17-71 

5PO* 357 .... 5100 M.. 5M2 

7HO 63 .... 9-00 .... 9-19 

2Fe20»,3PO« + 2(2NaO,PO») + 7 Aq. 700 .... 10000 

G. Sulphide op Iron and Sodium. — 1. Formed by fusing 2 parts of 
iron pyrites with 1 pt. carbonate of soda. — 2. By fusing sulphide of 
antimony with carbonate of soda, charcoal^ and iron.*— Deep yellow, 
forms a black paste with water. (Berthier.) 



IRON AND BARIUM. 273 

H. Basic SuLPnATE op Ferric Oxide and Soda.— -Formed by the 
weathering of iron-pyrites injected into alum-slate. Massive^ exhibiting 
an earthy fracture, and yielding a light yellow powder; perfectly insoluble 
in water, sparingly soluble in hydrochloric acid. (Th. Scheerer, Pogg. 
45, 190.) 

Schccrer* 

NaO 31-2 .... 6-00 .... 5-20 

4Pe«0» 3120 ..- 49-98 •... 49-63 

5S09 200-0 .... 32-04 •..• 32-44 

9H0 81-0 .... 12-98 .... 13-11 

NaO»SOS-f4(Fe'OS,SOS)-f9Aq. 624-2 .... 100-00 .... 100-38 



Irok and Barium. 

By heating to whiteness a mixture of iron and baryta, strontia, or 
lime, with or without charcoal, Oay-Lussac & Th^nard did not succeed in 
combining the metal contained in either of these alkalis with the iron. 

, A. Allot of Iron and Barium.— Lampadius {Sckw, 15, 146) by 
heating to whiteness a mixture of 1 pt. baryta with 1 pt. of iron-plate 
and \ pt. charcoal-dust, obtained a metal which, when exposed to the air, 
soon crumbled to pieces, and was converted into baryta and ferric oxide.*—* 
Clarke {fi%J(h, 62, 874) fused 2 jpts. barium with 1 pt. iron before the 
oxy-hydrogen blowpipe, and obtained a brittle, lead-coloured mixture. 

B. Ferrate op Baryta.-— Aqueous ferrate of potash yields with 
dilute solutions of baiytsrsalts in excess, a bulky, deep carmine-coloured 
precipitate which may be washed and aiterwards dried at 100® without 
changing colour. (D. Smith.) The precipitate when fresh is cochineal- 
coloured, but after washing and drying, it is rose-coloured or brick-red, and 
is found to have absorbed a small quantity of carbonic acid from the air. 
(Wackenroder.) When carefully heated, it merely loses water and turns 
green; at a higher temperature, it likewise gives off oxygen gas and loses 
its colour. Before drying, it is decomposed by acids, even by carbonic 
acid, — more slowly by sulphuric acid than by some others. (D. Smith.) 
When treated with siuphnrio acid, it retains a pale red colour. (Wacken- 
roder.) 

DrUd at lOO"". Sniitli. 



2BaO 

FcHi* .M ..M...... 

30 


153-2 
780 
24 
18-0 


.... 56-08 
.... 28-55 

.... 6-59 


M...... 

.«M.... 


52-81 

31-26r 

9*66 


2HO 


6-33 


2(BaO,FeO> + Aq.) 


2732 


.... 10000 


....*••* 


100-00 



C. Sulphide op Iron and Barium.-^IO parts of sulphate of baiyt% 
heated to whiteness in a charcoal crucible with 10 pts. diy ferrous sulphate, 
yield 11*5 pts. of metallic sulphide, — ^therefore 62*6 p. c. sulphide of 
barium to 37*4 sulphide of iron. After fusion it exhibits a close fracture, 
dark grey colour, and metallic lustre. (Berthier.) 



vol. t. 



274 IRON. 



Iron and Galcivm. 

Aqueoas ferrate of potash does not precipitate the salts of strontiai 
lime^ or magnesia. (D. Smith.) 

A. Hypophosphitb op Ferrio Oxide and Lime. — An aqneons solu- 
tion of phosphitei of lime is boiled for a considerable time with excess of 
ferrons oxalate^ the mixture left to cool in a closed vessel, then quickly 
filtered and evaporated in vaono over oil of vitriol. — Greenish crystalline 
crusts, which, when heated, give off spontaneously inflammable phos- 
phuretted hydrogen gas. Contains 31 '37 hypophosphite of lime, 44"73 
hypophosphite of ferrous oxide, and 23*90 water. (H. Rose, Pogg* 12, 294.) 

B. Sulphide op Iron and Calcium. — When 20 pts. crystallized 
gypsum and 20 dry ferrous sulphate are heated to whiteness in a 
charcoal crucible, i7'23 parts of metallic sulphide are obtained, in the 
form of a fused, blistered, whitish-grey mass, having a faint metallic 
lustre. (Berthier.) 

Fluorspar fuses readily with ferric sulphate; but the mixture decom- 
poses immediately afterwardef, with evolution of sulphuric acid« (Berthier, 
Ann, Gkim. Fhys, 43, 301.) 

Iron and MAONSsiuic. 

A. Allot op Iron and Magnesium. — Magnesia moistened with oil 
and brought to the melting point before the oxy-hydrogen blowpipe, fuses 
with iron into a brittle alloy, which exhibits the metaUio lostre, and 
yields to the file. (Clarke*) 

B. Carbonate of Ferrous Oxidb and Magnesia. — MmUine-wparj 
which has the form of calcspir and a density of 3*30/ is, according to 
Stromeycr, MgO,CO»+FcO,CO». 

Carbonate of magnesia appears to render hydrated ferric oxide 
somewhat soluble in water. (Bisohof, «/. pr, Ghent, 2, 70.) 

C. Sulphate op Ferroso-ferrig Oxide astd Magnesia. — Bolryagme, 
— Hyacinth-red, oblique rhombic prisms ; sp. gr. 2.039. Contains from 
2*22 to 6*7] p. c. sulphate of lime, 26'88 to 17*10 sulphate of magnesia, 
35-88 to 39*92 ferroso-ferric sulphate, 6*77 to 6*85 basic ferric sulphate, 
and 28*28 to 31*42 water, including loss. (Berzelins <fe Haidinger, Pogg, 
12, 491.) 

Iron and Cerium. 

Carbide of IrcXn and CBRiini.-^A mixture of eeri^ and ferric 
Qxides heated to whiteness with charcoal, yields a green, poroils^ magnetioy 
itery brittle mass^ which appears metallis when filed. (GhiJio.) 

Iron and Glucinum. 

A. Alloy op Iron and Glucinum. — Obtained by Sir H. Davy: 
1. By heating to whiteness a mixture of glucina, iron, and potassium; 



.1 



IRON AND ALUMINUM. 375* 

2. Bj brining slightlj moistened glncina inclosed in an atmosphere of 
hydrogen into the circuit of a thousand-pair voltaic battery with double 
plates, the negatire pole being formed of an iron wire, which was fused 
by the action of the current. 

B. Carbidb of Iron and Glucinum. — By raising a mixture of 
glucina^ iron, and lamp-black to an intense white heat. — Whiter and less 
ductile than iron. Bissolres in acids, forming double salts of iron and 
glucinum. (Stromeyer.) 

Ibon and AhXfuansM. 

A. Allot of Iron and ALUMiNuk.— Prepared by Davy in the same, 
manner as the alloy of iron and glucinum (method 2). — Whiter than 
iron. When immersed in water, it causes efierrescenoe, and becomes 
covered with a white powder. Dissolves in hydrochloric acid, forming a 
mixture of hydrochlorate of ferrous oxide and hydrochlorate of alumina. 

B. Aluminaxe of Ferrous Oxide. — Zeilanite. — Spinelle (III., 328) 
in which part of the magnesia is replaced by ferrous oxide. — Black octo- 
hedrons {Figs. 2 and 6). Sp. gr. from d'6 to 3*8. Harder than quartz ; 
translucent or opaque; yields a greyish-green powder. Does not fuso 
before the blowpipe, but dissolves in borax or in microcosmic salt, forming 
a glass coloured by iron, and scarcely acted upon by acids. 

Abich. Abich. 

At. Zeilanite, Ural. Iscrwiese. At. Vcsuriua. 

MgO.... 2 .... 400 .... 17-45 .... 17-58 .... 17-70 .... 9 .... 180 .... 24*69 .... 2594 

FeO .... 1 .... 350 .... 15-27 .... 13*97 .... 19-29 .... 1 .... 35 .... 4-80 .... 506 

A1»0» 3 .... 154-2 .... 67-28 .... 6527 .... 59-66 .... 10 .... 614 .... 70-51 .... 67*46 

229-2 ....100-00 .... 99-32 .... 9844 729 ....10000 ....100*84 

Addendum. — CTUorospinelle, from Slatoust. — Regular octohedrons; 
sp. gr. 3*593; hardness equal to that of topaz. Translucent at the edges, 
^rass-green,' yielding a greyish-green powder; assumes a transient brown- 
ish-green colour when heated. Infusible before the blowpipe; fuses with 
carbonate of soda to a greyish-white mass; in the state of powder, it dis- 
solves readily in borax or in microcosmic salt, forming a green glass, 
colourless after cooling. It may be regarded as spinelle, MgO,AFO^, in 
which part of the alumina is replaced by ferric oxide, as is the case, 
though, to a smaller extent, in the Zeilanite from Iserwiese. (G. Rose, 
Fogg. 50, 652. 

At ChlorotpinelU, G.Rose. At G.Rose* 

CaO ... .... .... .... 0*27 

MgO..! 12 r. 240-0 ".! 27-17 Z 26*77 .... 7 .... 140-0 .... 26-e() .... 27-49 

\^UVf •... .... .... .... V mt .... .... .... .... V 9m 

Fe«C)» 1 .... 78-0 .... 8-83 .... 8*70 .... 1 .... 78*0 .... 14*82 .... 14*77 
M^Cfi 11 .... 565-4 .... 6400 .... 64*13 .... 6 .... 308*4 .... 58*58 .... 57*34 

883-4 ....100-00 ....10014 526-4 .... 100*02 .... 10012 

IT Ebelmen, by exposing a mixture of 3*30 pts. alumina, 2*57 
ferric oxide, and 2*50 ooracic acid, to the heat of a pottery furnace, 
obtained a mass^ the whole surface of which was covered with intersecting 

T 2 



276 



IRON. 



Vis^iii broi^n^ transparent or translucent laminse ; they were hard enoagh to 
scratch quartz. The compound Al*O^FeO has lately been discoyered by 
Lippe, and named HencinUe. {Ann. Pharm. 68, 266.) IT 

C. Carbide of Iron and Aluminum. — Formed by raising an inti- 
mate mixture of alumina and carbide of iron d, (p. 219) to an intense 
white heat.— Very brittle and white; yields by analysis, 6*4 p. c. alumina. 
When fused with 1 5 parts of steel, it forms an alloy resembling Indian 
steel. (Faraday & Stodart.) 

D. Sulphate of Alumina and Ferrous Oxide. — a, A specia of 
Feather-iaU, — Formed by the weathering of iron-pyrites diffused through 
shtte-clay in the abandoned mines of Hurlet and Gampsie. — Asbestns-like 
mass, consisting of colourless, silky fibres, which turn brown in moist air, 
are easily soluble in water, on the eyaporation of which, crystals of 
green yitriol separate out, the alumina remaining in the mother-liquid. 
(Phillips, Ann. PhU. 21, 446.) 

PhiUips. 



SFcO 2I0'0 

Al*03 51-4 

8SCP 320-0 

48HO 432-0 



20-72 

507 

31-58 

42-63 



**•••..• 



20-7 

5-2 

30-9 

43-2 



6(FcO,SO») + Al»0»,2SO» + 48Aq. 1013-4 .... 10000 1000 

h. Another kind of Feather -wit. — ^White, silky, asbestus-like bundles 
of fibres, which have a st3rptic taste, giye off water when gently heated, 
fuse readily, and dissolve perfectly in water, forming a colourless solution. 
Orip^in unknown. (Berthier, Schw, 33, 472.)— A similar composition is 
that of MountainrbtUUrj which occurs at Wetzelsteir near Saalfeld in 
white, botrymons, and kidney-shaped masses. (Brandos, Sckuf. 39, 417.) 



NH» 

NaO 

MgO 

2FeO 70.0 

A120» 51-4 

SSC 200-0 

27HO 243-0 







Berthier. 




Brandes. 






Feather^ 




Mamntam 






soli. 




hater. 




*••• 






1-78 




••>. 




*••« 


0-72 




••*■ 


0-8 


*••• 


0-81 


12*40 


»••« 


120 


.... 


1018 


911 


.■•• 


8-8 


*••• 


Ml 


35-44 


*•*. 


34-4 


«... 


35-33 


43-05 


*••. 


44-0 


.••. 


44-13 



2(PtO,S03) + Al«0»,3SO» + 27Aq. 564-4 .... 10000 



100-0 



100-00 



c. Anothef* kind of Feather-aaUf corresponding in composition to alum. 
From the quicksilver mine at Morsfeld. Yellowish-white, silky mass, 
consisting of soft parallel fibres. (Rammelsberg, Fogg. 43, 399.) — The 
same salt is obtained artificially by mixing the solutions of green vitriol 
and sulphate of alumina with a large excess of sulphuric acid. The mix- 
ture, WD en put into a porcelain basin with rough sides, and left to evapo- 
rate in a warm place, effloresces in long, silky threads, united in bundles, 
which are very apt to creep over the edge of the vessel (Klauer, Ann. 
Pharm. 14, 261.) 



IRON AND SILICIUM. 277 

Rammelsberg/ KUuer. 

KO .....•». .... ....1 0-43 

MgO .... .... 0-24 

FeO - 35-0 .... 7-57 .... 9-37 .... 7*88 

APO» 51-4 .... 1112 .... 10-91 .... 11-30 

4SO» 160-0 .... 34-60 .... 3602 .... 3579 

24HO 216-0 .... 4671 .... 43-03 .... 4503 

FeO,SO» + Al*O»,380» + 24Aq 462*4 .... 100-00 .... 100-00 .... 10000 

d. Feather-Balt containing Magnesia, Formed by the weatbering of 
iron-pvTites iDJected into the slate below Fort Aries. White^ greenish, 
or yellowish concretion, which reddens litmus, has a styptic taste, fases 
when heated, and then swells up, leaving a reddish, porous mass. (Bouis, 
J. Chim. Mid., U, 628.) 



MgO. 
FeO . 
APO>. 
380». 
15H0 









Bouis 


200 


•«■• 


5-54 


5-30 


350 


»••• 


9-68 


10-19 


51-4 


•••• 


14-22 


13-15 


1200 


*••• 


33-21 


32-18 


1350 


•••• 


37-35 


39-18 



MgO,80» + FeO,SO«+Al»0>,SO»+15Aq. 361-4 .... 100-00 10000 

E. Sulphate of Alumina and Ferric Oxide. — ^When hydrate of 
alumina recently prepared and still moist, is agitated with an aqueous 
solution of tersulphate of ferric oxide, it takes from that solution the 
whole of the ferric oxide, together with the greater part of the sulphuric 
acid, and — ^if the iron-solution be in sufficient quantity — is thereby ex- 
panded to four times its original bulk. A small quantity of alumina is 
transferred to the liquid. Any excess of the iron-solution remains unal- 
tered. The resulting compound washed with hot water, dissolves easily 
in cold dilute sulphuric acid, with difficulty in cold dilute nitric or hydro- 
chloric acid ; potash abstracts from it a large proportion of the alumina. 
(Anthon, Repert. 77, 114.) 

Hydrate of alumina similarly treated with hydrochlorate, nitrate, or 
acetate of ferric oxide, is conyerted into a brown, viscid jelly; the dark 
brown supernatant liquid, which contains alumina^ yields a jelly on 
evaporation; with oxalic acid, it forms small, light brown flakes, and with 
ferrocyanide of potassium, a brown gelatinous precipitate, which turns 
blue on the addition of hydrochloric acid. (Anthon.) 



Iron and Silicium. 

A. SiLiciDB OF Iron. — 1. Prepared by Davy similarly to the alloy 
of iron and alumina. When treated with hydrochloric acid, it deposits 
silica. — 2. Clarke obtained a white metal by exposing silica in contact 
with iron in a charcoal crucible, to the flame of the oxy-hydrogen blow- 
pipe; and by using a small quantity of iron, he obtained silicium almost 
free from iron. — 3. When pure iron is fused in an earthen crucible, an 
alloy is formed which contain^ 0*54 per cent, of silicium, and is more 
difficult to file and hammer than pure iron. (Boussingault, Ann. Chim. 
Phys. 16, 15.)— 4. When iron filings are heated to whiteness with fluo- 
ride of silicium and potassium, the products are fluoride of potassium, 
fluoride of iron, and silicide of iron. Hot water dissolves out the two 
former, and leaves the latter. Silicide of iron 4i«9QW^ in acids, even in 



I 

1 



278 IRON. 



^ydroflaosQieio aeid, the sillciam being oxidated. When exposed to^ the 
air in a moist state, it is converted into a rusty yellow-ochre. (Benselius.) 



B. SiLiCATB OF FtiRROUS Oxi]!>E, or Ferrous Silicate. — a. DisilicaU. 
— ^Often produced in the conversion of oast into wroueht iron, and in the 
refining of coarse copper; in the latter case, it is mixed with the sulphides 
of copper and iron. Exhibits the same crystalline form with the same 
cleavage-planes, likewise the same lustre and hardness as Chiysolite 
(III., 395) even when disilicate of lime is mixed with it. Hydrochloric 
acid extracts the ferrous oxide, and leaves the silica (in the form of a jelly: 
Kobell) undissolved. (Mitecherlich, Ann. Ohim. Phyd, 24, 35di Walchney, 
Schw. 39, 71; (>omp. Miller, Pogg. 23, 559.) 

Mitscherlich. Walchner. 

f ^ — \ /■— \ ■ \ 

a. h, e. d. 6. 

KO .... .... .... 0-20 .... 0-29 .... 0-19 

MgO .... 0-65 .... 1-90 .... 1-41 .... 1-31 

MnO .... .... 1-30 .... 2-65 .... 1*46 

2FeO .... 70 .... 69-31 .... 67*24 .... 6907 Fe^O* 61-23 .... 6204 .... 6332 

li^CIU>....... .... .... .... .••....• .... •*.. B Uv. 

A.1 O^ .... a... •••. .... ........ I'OO .... •'.. 1 ^V 

8i03 31 .... 30-69 .... 3M6 .... 3Q-93 3296 .... 32*35 .... 2925 



101 .... 10000 .... 99-05 .... 10000 99-15 .:.. 98*74 .... 9943 

a. are crystals from iron-works; b. fron^the copper refinery; the admixed 
sulphide of iron and sulphide of copper have been allowed for in the 
analysis ; c. from the iron- works at Dax in the Pyrenees, sp. gr. 3 7 ; 
d, from the iron-works at Bodenhausen in the Harz; very much like 
hyalosiderite, sp. gr. 3*529; e. from the copper-refinery at Lauterthal in 
the Harz, sp. gr. 3-87. 

To this head belong also Uyalosideriie and FayaliU, excepting that a 
large quantity of the ferrous oxide is replaced by magnesia and other 
bases. Hyalosiderite has the form of chrysolite; sp. gr. 2*875; harder 
than apatite, yellowish-bro^n; translucent at the edges, where it exhibits 
a hyacinth-red colour. If not naturally magnetic, it becomes so when 
heated to redness, when it also turns black ; at a higher temperature, it 
fuses to a black magnetic globule. With borax or microcosniic salt, it 
gives the reactions of iron, and with microcosmic salt, immediately a 
skeleton of silica. It dissolves with difficulty in cold, concentrated 
hydrochloric acid, and yields a jelly on evaporation. (Walchner, Schw, 
39, Q5.) — Fayalite is sometimes of crystalline structure, sometimes fused 
and blistered; sp. gr. 4*138; softer than quartz, greenish-black, and strone^ly 
attracted by the magnet. Fuses very easily and quietly to a metallic 
globule, with evolution of sulphurous acid; dissolves readily in borax and 
in microcosmic salt. Strong- fuming nitric acid converts it into a jelly; 
but when this jelly, after washing with water, is boiled with carbonate 
of potash, which dissolves the gelatinous silica, there remains another 
mineralt insoluble even in boiling oil of vitriol ; this latter mineral was 
therefore intimately mixed with the soluble mineral, the purer Fayalite. 
(0. G. Gmelin, Fogg. 5J, 160.) 



KNEBELITB, ITROSMAUTE. 



279 



KO .... 

4MgO 

MqO 

27eO 

88iO> 

A1«0» . 

Ci«0» . 



Byalo9id0lHi€. 



80 

70 
93 






32*92 

28-80 
38*28 



WilchBO*. 

2-79 
32*40 

0*48 
29*71 
31*64 

2*21 

traoe 



243 



100*00 



99-23 



Soluble part qfFayaUte, 

CaO 

MnO 

2FtO 70 .... 

CuO 

PbO 

iSiO* 31 .... 

APO« 

rcS .... 

S and CI 



69*31 



30-69 



C. 6. Gmelin. 

2*94 

65-84 

0-60 



24*93 
1*84 
2-77 



t».t 



Fellenberg. 

0-43 

0-79 
62-57 

0-32 

1-71 
31-04 

3-27 

trace 



101 



100-00 



98-92 



100-13 



In Walchner's analysis^ tbe 29*71 denotes not ferrons but ferroso^ferrio 
oxide.— The insolnble portion of Fayalite exhibits such diyersities of 
composition that it cannot be lednoed to calculation, 

KnehelUe, — FeO, MnO, SiO*. — ^Decomposed by hydrochloric acid, witb 
separation of gelatinous silica. (Ddbereiner, Schw, 21, 41.) 



MnO 
FcO.. 
SiO«.. 



Knebeme. 
36 .... 35-30 
35 .... 34-31 
31 .... 30-39 



Dobereiner. 
35-0 
32-0 
32-5 



102 



10000 



99*5 



6. Monosilicate. — a. Sometimes found in the slag of the blast-furnaces 
(partly mixed with monosilicate of lime) in greenish, often transparent 
crystals corresponding to those of Augite. (Mitscherlich.) 

When a mixture of 1 At. SiO' and 1 At. Fe'O' is fused for an hour 
in a charcoal crucible, iron is reduced, and a slag (a) formed, resembling 
the slag produced towards the end of the process of converting cast into 
wrought-iron; composition = FeO, SiO' nearly. The iron reduced in the 
process is not pig-iron, but very malleable, partly of specific gravity 
8*089; the ferrous silicate appears therefore to prevent the combination 
of carbon and silioinm vnth the iron.^-By fusion for several hours in a 
blast-furnace, more iron is reduced from the slag, likewise malleable and 
containing only 0*59 per cent, of carbon, together with a trace of silicium; 
and the slag I has very nearly the composition 2Fe0^dSiO*. (Sefstrom, 
J. techn. Chim. 10, 178.} 



FeO. 
SiO*. 



Stag^ a. 
35 .... 53*03 
31 .... 46-97 



SefstrOm. Slag b, Sefstrom. 

. 51-2 2FeO 70 .... 42*94 .... 46*05 

. 49-6 3SiO» 93 .... 57-06 .... 5395 



FcO,8iO» 66 



10000 



100-8 2FcO,3SiO» 163 



100*00 



100-00 



FyromalUe. — 1 5(MnO, SiO») + 1 5(FeO,SiO') -f Fe'CP, 3Fe'0», 3 Aq. % 
•—Regular six-sided prisms, the lateral edges twice truncated. Cleavage 



280 IRON. 

perpendionlar to the axis; less distinct puallel to tlie lateral faces. 
8p. gr, 3*081; yellowish-brown witfaont, ffreenish-yellow within; opaque; 
yields a light green powder* Before ue blowpipe it assumes a black- 
brown colour^ gives off rapours of water, hydrochloric acid, and sesani- 
chloride of iron, and fuses to a black magnetic globule. Dissolves readily 
in borax, exhibiting the reactions of manganese and iron — ^with difficulty 
in microcosmic salt. Dissolves in nitric acid with separation of silica. 
(Hisinger, Sehw. 23, 63.) Hydrochloric acid, after lone digestion, decern* 
poses it completely, without forming a siliceous jelly. (H. Rose.) 











Hidnger. 


vH\^ •*...•••■*••• 


M. 


.... 




1-21 


15MnO 


... 6400 


...« 


22-35 


23-45 


ISFcO 


... 525-0 


.... 


21-73 


20-78 ♦ 


«IVDIvF^ •••*•••>«< 


... 930-0 


.... 


38-49 


35-85 


4F«»0» 


«. 3120 


..«• 


12-91 


12-34 ♦ 


3{Cl-0) 


82-2 


.... 


3-40 


2-91 


3HO 


270 


.... 


1*12 M...... undetermined 



2416-2 .... 100-00 



e. Six-fifths Silicate, — HorrMendes rich in Iron. — «. AffvedsoniU. 
5(NaO; CaO; MgO; MnO; FeO). 6SiO».—tt^:tt= 123^ 55'. Fuses even 
in the flame of a candle; boils up strongly before the blowpipe, and jrields 
a black magnetic globule. Not soluble in acids or in caustic potash, 
(v. Kobell, J.pr. Chem. 13, 3.) 

















KobeD. 




At 












IVon QieenlaBd. 


NaO 


4 


•.*• 


124-8 


•.•• 


8-77 




8-00 


CaO 


1 


.••• 


280 


.... 


1-97 


•..•a... 


1-50 


MgO 




.... 




.... 




..•* •••• 


0-42 


AAnU ••.......*•• 




.... 




.... 




• »...M« 


0-62 


FcO 


15 
24 




525-0 
7440 


•«.• 
•«*• 


36-93 
52-33 


.....M* 


36*12 


SiO» 


49-27 


A1«0> 




•.i. 




•M* 






2-00 


CI 




.... 




•«.• 






0-24 



1421*8 .... 100-00 . , 98-17 

p. Ae^^ne.—5{K0; NaO; CaO; MgO; MnO; FeO), 6 SiO».— Re- 
sembles hornblende in outward appearance. Fuses to a black globule; 
forms a green transparent bead with a large quantity of borax, and a 
black bead with a still larger quantity. With microcosmic salt it forms 
a green glass and a skeleton of silica. Dissolves abundantiy in carbonate 
of soda, forming a brown opaque bead. Contains titaniferous iron injected 
into it. (Plantamour, J. pr. Chem. 24, 300.) 

* Hisinger found, on the whole, 35*48 p.c. sesqniozide of iron, of whidi, howeter, 
he supposed that the greater part was contained in the mineral in the form of protoxide. 
In the above calculation, ^ of the tesquioxide found by Hisinger Is reckoned as prot* 
oxide, and the remaining f^ as sesquioxide. 



FERRIC SILICATE. 



281 



















At. 










Ennark. 


KO 




• •!• 

• ••« 

• •«• 

• ••« 


47-2 
124-8 
112-0 
1000 




2-54 

6-70 

6*0.3 

• 5-37 


..... 2*96 


NaO 




7«79 


c«o 




5-91 


MgO 


»••• V 


5-88 


MnO 


»••■ m 


• •«• 


360 




1-93 


2-07 


PcO 


.... 12 


• ••• 


4200 




22-56 


24-38 


SiO* 


SO 


• ••• 


9300 




49-96 


46-57 


APO» 


■••• m 


• ••• 


51-4 




2-76 


I...M 9-41 


TlO« 


fm X 


»••• 


40-0 




2-15 


2-02 


P 


»••• 


• ••• 






■• 


>*..•• ir&oo 



1861-4 



100-00 



100-99 



If from the 27 atoms of the stronger base there be deducted 1 At. for the 
titanic acid and 1 At. for the alamina, there remains 25 At. base to 30 
At. silicic acid = 5:6. 

d. Five-fourthi Silicate. — KrcJeydoUte or Blue Ironstone.^NzOjJAsQ), 
2SiO*+d(FeO^ SiO^ + 5 Aq. — Very much like asbestus, made up of long 
and soft fibres; sp. gr. 3*20; hardness equal to that of fluorspar; indigo- 
blue in the mass; lavender-blue in single fibres. When gently ignited 
out of contact of air, it gives off water, diminishes in bulk, and becomes 
dull, retaining, however, its fibrous texture. When heated in contact 
with the air, it becomes red-brown, and then brown-red, but if afterwards 
heated in hydrogen gas, it regains its former aspect. At a strong red 
heat, even m the flame of a spirit-lamp, it fuses to a black, swollen, 
strongly magnetic glass; from which hydrogen gas with the aid of heat 
separates metallic iron. With borax it gives the reactions of iron. Does 
not dissolve in sulphuric, hydrochloric, or nitric acid, either cold or hot. 
(Stromeyer & Hausmann, Schw. 64, 50.) 

Stromejor. 





At. 










NaO 


2 


.... 


62-4 


...a 


6-88 


CaO 


.. 


.... 




.... 




MgO 


1 


..*• 


20-0 


.... 


2-20 


Mii»0» 


•a 


.... 




.... 




FeO 


9 


.*•• 


315-0 


.... 


34-71 


SiO* 


... 15 


.... 


465-0 


■ M. 


51-25 


HO 


5 


.... 


45-0 


• «*. 


4-96 



7-03 


to 


7-11 


0-02 




0-05 


2-32 




2-64 


017 




0-02 


33-88 




34*38 


50-81 




51*64 


5-58 




401 



907-4 



100-00 



99*81 



»9 



99-85 



e. Quadroiilieate.'^The solution of protochloride of iron in less than 
2500 parts of water gives a greyish-green precipitate with aqueous quad- 
rosilicate of soda. (Walcker.) 



C. SiLicATB OF Ferric Oxidb, or Ferric Silicate.— a. ManosiliecUe* 
—Iron-cinder from the Himmelfahrt mine near Freiberg. — Mn'0^,SiO'+ 
Fe'O', SiO'+12 Aq.— Deposited from the water of the mine, which con* 
tains the sulphates of ferrous oxide, manganous oxide, and lime with 
excess of acid, and has probably driven out hydrofluoric acid from 
fluorspar, which dissolved the quurtx. Of stellate-fibrous structure, in- 
clining to the conchoidal; sp. gr. 2*28. When heated it gives off water, 
having an acid reaction, but not capable of etching glass. Water extracts 
traces of sulphates from it Dissolves quickly in hydrochloric acid, form- 
ing a brown, or if previously heated, a yellow solution, with evolution 
of chlorine and separation of gelatinous silica. (Karsten, J, pr, Cheuiw 

32, 1.) 



882 



IBON. 



Mn«0» 
Fe«0» 
2SiOS 
12HO 



80 


• ■•• 


24-32 


78 


• ••• 


24 01 


62 


«••• 


18-84 


108 


• ••• 


32-83 



KcnteD* 
25*01 to 26-54 



22-90 
18-98 
33-00 






»f 



21-00 
1807 
32-82 



328 



100*00 



99*89 



9J 



98*43 



h. Se9^uiUcaU.—TeUow Earth from Amberg.— 2(FeKHj Al'O'), 
3SiO'+4 Aq. (Kiihn, Sckw, 51, 466.) 



YtUow Earth. 

MgO 

5Fe«0» 3900 .... 36*79 

3AP0» 154-2 .... 14*54 

12SiO« 372*0 .... 85*09 

16HO 1440 .... 13*58 



Ktthn. 
1-38 
37*76 
14-21 
33-23 
13*24 



1060*2 



100*00 



99*82 



c. Bisilicate. — BinngeriU, — Fe'O*, 2SiO*+4 Aq. — Amorplioiis, with 
an uneven^ conchoidal fractare. Black, but produces a yellowisb-brown 
powder Oives off water when heated; the blowpipe-flame rounds it off 
at the edges, and renders it dull and magnetic (Hismger, Pogg, 13, 505.) 
Hydrochloric acid decomposes it, with formation of gelatinous silica. In 
the analysis of Hisingerite from Bodenmais (also <^ed ThrauliU), the 
admixed magnetic pyrites was deducted by Hisinger, and likewise by 
Kobell. {Poffg. 14, 467; Schw. 62, 198.) 



2SiOV 
4HO . 



HUm§triie, 
78 .... 44*38 

62 .... 35-23 
36 .... 20-45 



Hisingter. 

BUdarhyttan. 

45-95 

3630 

20-70 



HisiDger. 



51*53 
31-78 
20-00 



KobeD. 



50*86 

31*28 
1912 



176 .... 100-00 



102^95 



103-31 



101-26 



In the mineral from Riddarhyttan, Hisinger found 44-39 per cent., and 
in that from Bodenmais, 49*87 per cent, of Fe'OS which, in the above 
analyses is reckoned as Fe'O'. Kobell found in the mineral from Boden- 
mais, 5*7 per cent, of FeO, which, however, he supposed to arise from the 
presence of magnetic pyrites. This perhaps is the origin of the excess of 
ferrio oxide over the silica, which is apparent in the analyses; or, on the 
other hand, this excess may arise from the actual composition of Hising- 
erite: if that be the case, the mineral may perhaps be represented by the 
formula : — 2Fe*0^ 3SiO* + 4 Aq , analogous to Yellow Earth. 

The Ochre which is deposited by the hot spring at Lucca on exposure 
to the air, probably from ferrous silieate contained in it, and which dis- 
solves in hydrochloric acid with separation of gelatinous silica, contains 
[besides water 1] 57'17 p. o. ferrio oxide to 42*86 silica. (H. Davy, 
Schw. 85, 78.) \¥eO^, 2SiO* requires 55*71 p. o. ferric oxide to 44*29 
silica.] 

d. r«*«aica<*.— i\roneront<(a.— FeK)*,3SiO»+ 5 Aq.— Massive, with a 
splintery or earthy fracture; translucent or opaque; varies in colour from 
siskin-green to straw-yellow. When immersed in water, it gives off 
babbles and becomes transparent. Before the blowpipe it decrepitates, 
turns yellow, then brown, then black, and acquires magnetic properties, 
but without fusing. Itisoluble in cold acids, but soluble in hot sulpfaurio, 
hydrochloric, or nitric acid, with separation of gelatinous silica. (Berthier, 



NONTRONITB/ ARTHOSIDERITE. 283 

lAnn. Ohiv^ Pky$. 86, 22; Jaoqiielain, Ann. 0km. Phyi,' 66, 101; 
Biewavd, J. pr. Chem. 11, 162.) 









^oii^roitf/#« 




fiertbier. 




Jacqnelaiiit 




Biowend. 




At 












St. Faidoaz< 




Moatmort. 


Andreasborg. 


CaO 




• •«• 




••♦1 




f ••• 




•••f 


0-19 




trace 


MgO 




• ••• 








••«• 


21 










MnO 




• • •• 








• ••• 




• ••• 






trace 


ZnO 




• «■• 








• •*• 




■••• 


trace 






CbO 




• ••• 








• •■« 




»••• 


0-90 






Fe»0«.. ... 


■••■« m 


• *»« 


78 




3611 


• ••• 


290 


• ■•• 


35-69 




37-30 


A1«0» 




• ••• 








• ••• 


3*6 


■ ••■ 


3-31 






SiO» 


3 


• ■•• 


93 




43*06 


• ••• 


440 


• ••• 


41-31 




41-10 


HO 


5 


• ••• 


45 




20-83 


• •■• 


18-7 


• ••• 


18-63 




21-56 


Clay 




• ••• 








• ••• 


1-2 


• ••• 














216 


•••1 


10000 


••i« 


98-6 


■••• 


100*00 


• ••• 


09*96 



e. Quadr<mHcaU.—Antho9iderUe.^VeHfi, 4SiO>+ Aa f-^omposed of 

soft fibres; sp. ffr. about 8*0; gives sparks with steel; ochre-brown^ 

transluoent in thin fragments. (Hansmann & Sohnedermann, Fogg. 

52, 2d2.) 

AnikoiiderHe. Sohnedermann. 

Fe»0» 78 .... 36-97 34-99 

4SiO 124 .... 68-77 60-03 

HO 9 ...« 4-26 3-59 

211 .... 100-00 98-66 

When qaadrosilipate of eoda is gradually added to hydroohlorate of 
ferric oxide, the precipitate, as it forms, is immediately re-dissolved, with 
the exception of a small quantity of silica, and the liquid acquires a d^rk 
colour. On evaporating the liquid, a red-brown mass is left, translucent 
at the edges, and exhibiting a conchoidal fracture. Water causes it to 
decrepitate, and extracts from it chloride of sodium, together with the 
excess of ferric chloride, while ferric silicate is left behind in the form of 
a light yellowish-brown powder, from which hydrochloric acid extracts 
the whole of the ferric oxide. — With excess of tersulphate of ferric oxide, 
quadrosilicate of soda ^ives a precipitate only on boiling, but if the latter 
salt is in excess, the mixture solidifies in 24 hours. (Walcker, i^. Quart, 
J. o/Sc. 3, 371.) 

Silicate of Ferric Oxide with Carbonate of Potash. — Bihanc. — Olavher^s 
Iron-tree, — When a piece of perfectly dry protochloride of iron is im- 
mersed in soluble silica (obtained by fusing 1 pt. quartz and 8 pts. 
carbonate of potash, and dissolving the fused mass in water) thin, white, 
ribbon-shaped and thread-like columns or branches immediately rise from 
it to the surface of the liquid, and there form a kind of canopy; their 
colour is first green, and then brown, and they may be preserved if the 
liquid be carefully poured off from them. (R. B5ttger, J, pr. Chevn^ 
10, 60.) — ^Protochloride of iron forms white branches which rise perpen- 
dicularly, and after awhile turn green, then black, and lastly red by. 
oxidation. Sesquichloride of iron forms red branches. Green and blue 
vitriol likewise form trees. At the top of each branch is situated a 
gas-bubble, which, as it rises through the liquid, carries the iron-salt 
along with it. If the gas-bubble be removed, the growth of the branch 
is arrested. A large gas-bubble produces a thick, hollow branch termi- 
nating in a hemispherical summit. If a fresh gas-bubble carries i^i 



284 IRON. 

additioual quantity of iron-salt up through the hollow tube, the bubble 
then breaks through the summit and fills the whole liquid with crooked 
threads which spread out into a globe filled with gas. In the following 
table, a, gives the composition of the iron-tree obtained with protochloride 
of iron previously heated till it began to turn red; (. that formed by 
protochloride which had remained white; and c. that produced by the 
sesquichloride, after previous trituration and washing with water. 
(Mulder, J. pr. Chem. 22, 41.) 



Mulder. 



6PeK)* 468-0 

3SiO* 93-0 

2KO 94'4 

2CO* 44-0 







a. 


" ; 

0. «. 


66-91 


«•■• 


67*0 


.... 67-2 .... 66-7 


13-30 


•••• 


12-7 


.... 13-7 .... 13-8 


13-50 


••>• 


13-7 


14-7 


6-29 


• ••• 


6-6 


4 -ft 

• ••■ ■••• ^ O 



3(2Fe>0*,SiO>)-l-2(KO,CO*) 699*4 .... 100-00 .... 100*0 .... .... 100*0 

The carbonic acid was determined merely by loss. Mulder regards the 
compound as silicate of potash combined with carbonate of ferric oxide. 

(. With 4c At, €teid, — The precipitate formed with solution of silica 
and hydrochlorate of ferric oxide contains 25*3 p. c. ferric oxide, 45*3 
silica, 21 '1 potash, and 9*9 carbonic acid. (Mulder.) 

Double SvLicates containing Ferric Oxide and Alumina on the one 
hand, and Ferrous Oxide and others of the stronger hoses on the other. 

Chamoisite.—2{5YeO, SiO«) + A1*0', 3SiO* + 1 2 Aq.— Masave; fracture 
granular, uneven, or earthy; sp. gr. from 3*0 to 3*4; dark greenish-grey; 
magnetic. When heated, it gives off water, becomes more strongly 
magnetic and turns black, or if the air has access to it, reddish. Dis- 
solves readily in hydrochloric acid with separation of gelatinous silica, 
bhickened by asphalt. (Berthier, Schw. 33, 345.) 

Berthier. 
ChiunaisUe. I^com CbamoiwL 

lOFcO 350*0 .... 58-10 60-5 

APO» 51-4 .... 8-53 7*8 

3SiO* 93'0 .... 15-44 143 

12H0 108*0 .... 17-93 17*4 

602*4 .... 100-00 ZZ 100*0 

Pea-ore or Lenticular Grep Iron-stone from the Albinger pit near 
Kanderne.— 10FeO,3SiOH Al*0*,SiO»-*- 5 Aql— Nodules having a dia- 
meter varying from 1 line to 2 inches, splitting off in thin scales; sp. gr. 
31; dingy olive- green inclining to yellow. Dissolves slowly but com- 
pletely in aqua-regia, and yields gelatinous silica when evaporated. 
(Walchner, Schw. 51, 219.) 

Pea-ore, Walchner. 

trace trace 

61*61 „ 62*44 

8*58 „ 8-46 

20-85 „ 21-66 

8-18 „ 7*92 



CaOandMnO.... 








lOFcO 


3500 




61-36 


APO» 


51*4 




9-01 


4Si05 


124-0 




21-74 


5H0 


450 




7*89 



570-4 .... 100*00 99*22 ., 100-48 



Simpler, but less in accordance with the analysis is the formula 
3(3FeO, 6iO») + A1K)», SiOH5Aq. 



STILPNOMELANB, GEDHITE^ ILVAITE. 283 

iSjf«Zpnom«{an6--9(FeO,SiO')+APO^ dSiOH 7 Aq.— Laminar; sp. gr. 
from 3*0 to 3'4; Instrons, raven -black, yields a greenioh-black powder. 
Gives off ammoniacal water when heated; fuses with dii&cultjr before the 
blowpipe, into a black, shining globule; gives the manganese reaction 
with carbonate of soda